chore(deps): Upgrade filtermail to v0.7.5

## 0.7.5 - 2026-09-10

### Performance

- Pass HttpsClient by reference instead of cloning it
- Remove connection pool

### Refactor

- Do not evaluate smtp_write! argument twice
- Do not clone the Config unnecessarily

Signed-off-by: Jagoda Ślązak <jslazak@jslazak.com>

.github/workflows/ci.yaml

@@ -29,7 +29,7 @@ jobs:
           ref: ${{ github.event.pull_request.head.sha }}
           persist-credentials: false
       - name: download filtermail
-        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.7.0/filtermail-x86_64 -o /usr/local/bin/filtermail && chmod +x /usr/local/bin/filtermail
+        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.7.5/filtermail-x86_64 -o /usr/local/bin/filtermail && chmod +x /usr/local/bin/filtermail
       - name: run chatmaild tests 
         working-directory: chatmaild
         run: pipx run tox

.github/workflows/docs-preview.yaml

@@ -13,6 +13,11 @@ jobs:
   scripts:
     name: build 
     runs-on: ubuntu-latest
+    env:
+      # Pin the repository links in the docs to this pull request's head commit
+      # so that linkcheck resolves files which only exist on the branch so far.
+      # see doc/conf.py
+      DOC_GITHUB_REF: ${{ github.event.pull_request.head.sha }}
     environment:
       name: 'staging.chatmail.at/doc/relay/'
       url: https://staging.chatmail.at/doc/relay/${{ steps.prepare.outputs.prid }}
@@ -51,7 +56,7 @@ jobs:
           mkdir -p "$HOME/.ssh"
           echo "${{ secrets.CHATMAIL_STAGING_SSHKEY }}" > "$HOME/.ssh/key"
           chmod 600 "$HOME/.ssh/key"
-          rsync -rILvh -e "ssh -i $HOME/.ssh/key -o StrictHostKeyChecking=no" $GITHUB_WORKSPACE/doc/build/ "${{ secrets.USERNAME }}@chatmail.at:/var/www/html/staging.chatmail.at/doc/relay/${STEPS_PREPARE_OUTPUTS_PRID}/"
+          rsync -rILvh -e "ssh -i $HOME/.ssh/key -o StrictHostKeyChecking=no" $GITHUB_WORKSPACE/doc/build/ "${{ secrets.USERNAME }}@chatmail.at:${STEPS_PREPARE_OUTPUTS_PRID}/"
         env:
           STEPS_PREPARE_OUTPUTS_PRID: ${{ steps.prepare.outputs.prid }}
 

.github/workflows/docs.yaml

@@ -47,5 +47,5 @@ jobs:
           mkdir -p "$HOME/.ssh"
           echo "${{ secrets.CHATMAIL_STAGING_SSHKEY }}" > "$HOME/.ssh/key"
           chmod 600 "$HOME/.ssh/key"
-          rsync -rILvh -e "ssh -i $HOME/.ssh/key -o StrictHostKeyChecking=no" $GITHUB_WORKSPACE/doc/build/ "${{ secrets.USERNAME }}@chatmail.at:/var/www/html/chatmail.at/doc/relay/"
+          rsync -rILvh -e "ssh -i $HOME/.ssh/key -o StrictHostKeyChecking=no" $GITHUB_WORKSPACE/doc/build/ "${{ secrets.USERNAME }}@chatmail.at:"
 

CHANGELOG.md

@@ -1,5 +1,60 @@
 # Changelog for chatmail deployment
 
+## [1.12.0] - 2026-07-31
+
+### Breaking Changes
+
+- [**breaking**] Introduce configurable system limits to reject new address creation and limit imap/smtp connections.
+  Dovecot default connection limit lowered from 50k to 10k,
+  Postfix default connection limit lowered from 5k to 1k,
+  larger relays need to adjust their settings.
+
+### Features
+
+- Reduce maximal_queue_lifetime from 5d to 2d
+- Disable negative cache in unbound (#992)
+- *(mtail)* Add incoming_mailer_daemon_mail_count
+- *(postfix)* Disable processing of MIME headers
+- *(dovecot)* Advertise privacy_mail as admin contact, drop server comment
+
+### Bug Fixes
+
+- Set relay restrictions per smtpd service with default reject
+- Reduce maxproc for filtermail-transport LMTP client to 500
+- Core 2.50.0 does not have delete_server_after config anymore.
+- Check if all required ports are available for filtermail (#983)
+- Always deploy unbound.conf.d/chatmail.conf (#993)
+- Expire empty directories (#994)
+- Crypt-r dependency was declared for wrong Python version
+- Always overwrite /etc/resolv.conf, even if it is a symbolic link
+- Pass kwargs to files.put()
+- List Iroh proxy endpoints used by 0.35 and 1.0, drop stale /relay/probe from earlier versions
+- Fix port discovery when ss -tulpn shows dovecot before stats
+
+### Documentation
+
+- Add scripts/initenv.sh to upgrade instructions
+- Update overview diagrams (#995)
+- *(overview)* Remove mermaid styles from 'Accepting and delivering mail' (#1009)
+- *(README.md)* Clarify security enforcement (#1011)
+
+### Miscellaneous Tasks
+
+- *(ci)* Auto-trigger docker build on release tag push
+- *(acmetool)* Update let's encrypt ToS link to 1.8
+- *(ci)* Update doc staging upload path
+- *(ci)* Fix docs upload path
+
+### Refactor
+
+- *(postfix)* Remove unused "filter" lmtp service
+- Install dns-root-data instead of using unbound-anchor
+- *(deps)* Remove domain-validator dependency
+
+### Testing
+
+- Set socket security for IMAP and SMTP to "TLS" in "dclogin"
+
 ## [1.11.0] - 2026-05-15
 
 ### Breaking Changes

CONTRIBUTING.md

@@ -5,3 +5,6 @@ We use [git-cliff] to generate the changelog from commit messages before the rel
 
 [Conventional Commits]: https://www.conventionalcommits.org/
 [git-cliff]: https://git-cliff.org/
+
+To update client app version information,
+edit [chatmaild/src/chatmaild/defaults/appversions.json](chatmaild/src/chatmaild/defaults/appversions.json).

README.md

@@ -1,19 +1,24 @@
 
 # Chatmail relays for end-to-end encrypted email
 
-Chatmail relay servers are interoperable Mail Transport Agents (MTAs) designed for: 
+Chatmail relay servers are interoperable Mail Transport Agents (MTAs) designed for:
 
 -  **Zero State:** no private data or metadata collected, messages are auto-deleted, low disk usage
 
 -  **Instant/Realtime:** sub-second message delivery, realtime P2P
    streaming, privacy-preserving Push Notifications for Apple, Google, and Huawei;
 
--  **Security Enforcement**: only strict TLS, DKIM and OpenPGP with minimized metadata accepted
+-  **Security Enforcement**: Only connections with strict TLS are accepted;
+   all messages must be correctly signed with DKIM and OpenPGP-encrypted with minimized metadata.
+   There are experimental exceptions for no-DNS relays,
+   which are allowed use self-signed TLS certificates
+   and which do not need to DKIM-sign their messages.
+   Unencrypted messages are allowed in neither case.
 
 -  **Reliable Federation and Decentralization:** No spam or IP reputation checks, federating
    depends on established IETF standards and protocols.
 
-This repository contains everything needed to setup a ready-to-use chatmail relay on an ssh-reachable host. 
+This repository contains everything needed to setup a ready-to-use chatmail relay on an ssh-reachable host.
 For getting started and more information please refer to the web version of this repositories' documentation at
 
 [https://chatmail.at/doc/relay](https://chatmail.at/doc/relay)

RELEASE.md

@@ -1,15 +1,13 @@
 # Releasing a new version of chatmail relay
 
-For example, to release version 1.9.0 of chatmail relay, do the following steps.
+For example, to release version 1.13.0 of chatmail relay, do the following steps.
 
-1. Update the changelog: `git cliff --unreleased --tag 1.9.0 --prepend CHANGELOG.md` or `git cliff -u -t 1.9.0 -p CHANGELOG.md`.
+1. Update the changelog: `git cliff --unreleased --tag 1.13.0 --prepend CHANGELOG.md` or `git cliff -u -t 1.13.0 -p CHANGELOG.md`.
 
 2. Open the changelog in the editor, edit it if required.
 
 3. Commit the changes to the changelog with a commit message `chore(release): prepare for 1.9.0`.
 
-3. Tag the release: `git tag --annotate 1.9.0`.
+4. Open a PR with the new commit, merge it to main after review.
 
-4. Push the release tag: `git push origin 1.9.0`.
-
-5. Create a GitHub release: `gh release create 1.9.0`.
+5. In the web interface, create a GitHub release, tell it to create a new tag.

chatmaild/MANIFEST.in

@@ -1,3 +1,4 @@
+include src/chatmaild/defaults/*.json
 include src/chatmaild/ini/*.ini.f
 include src/chatmaild/ini/*.ini
 include src/chatmaild/tests/mail-data/*

chatmaild/pyproject.toml

@@ -8,9 +8,9 @@ version = "0.3"
 dependencies = [
   "iniconfig",
   "filelock",
+  "psutil",
   "requests",
-  "crypt-r >= 3.13.1 ; python_version >= '3.11'",
-  "domain-validator",
+  "crypt-r >= 3.13.1 ; python_version >= '3.13'",
 ]
 
 [tool.setuptools]
@@ -27,9 +27,6 @@ chatmail-quota-expire = "chatmaild.expire:quota_expire_main"
 chatmail-fsreport = "chatmaild.fsreport:main"
 lastlogin = "chatmaild.lastlogin:main"
 
-[project.entry-points.pytest11]
-"chatmaild.testplugin" = "chatmaild.tests.plugin"
-
 [tool.pytest.ini_options]
 addopts = "-v -ra --strict-markers"
 log_format = "%(asctime)s %(levelname)s %(message)s"

chatmaild/src/chatmaild/config.py

@@ -2,7 +2,6 @@ import ipaddress
 from pathlib import Path
 
 import iniconfig
-from domain_validator import DomainValidator
 
 from chatmaild.user import User
 
@@ -19,14 +18,12 @@ class Config:
         params = dict(params)
         raw_domain = params.pop("mail_domain")
         self.mail_domain_bare = raw_domain
-        self.ssh_host = params.pop("ssh_host", raw_domain)
 
         if is_valid_ipv4(raw_domain):
             self.ipv4_relay = raw_domain
             self.mail_domain = f"[{raw_domain}]"
             self.postfix_myhostname = ipaddress.IPv4Address(raw_domain).reverse_pointer
         else:
-            DomainValidator().validate_domain_re(raw_domain)
             self.ipv4_relay = None
             self.mail_domain = raw_domain
             self.postfix_myhostname = raw_domain
@@ -58,6 +55,7 @@ class Config:
         self.postfix_reinject_port_incoming = int(
             params.pop("postfix_reinject_port_incoming", "10026")
         )
+        self.doveauth_http_port = int(params.pop("doveauth_http_port", "10084"))
         self.mtail_address = params.pop("mtail_address", None)
         self.disable_ipv6 = params.pop("disable_ipv6", "false").lower() == "true"
         self.acme_email = params.pop("acme_email", "")
@@ -78,6 +76,16 @@ class Config:
         self.privacy_pdo = params.pop("privacy_pdo", None)
         self.privacy_supervisor = params.pop("privacy_supervisor", None)
 
+        self.max_load_1m = float(params.pop("max_load_1m", 5))
+        self.min_available_memory_mb = parse_size_mb(
+            params.pop("min_available_memory", "200M")
+        )
+        self.min_free_disk_space_mb = parse_size_mb(
+            params.pop("min_free_disk_space", "1G")
+        )
+        self.max_imap_connections = int(params.pop("max_imap_connections", 10000))
+        self.max_smtp_connections = int(params.pop("max_smtp_connections", 1000))
+
         # TLS certificate management.
         # If tls_external_cert_and_key is set, use externally managed certs.
         # Otherwise derived from the domain name:

chatmaild/src/chatmaild/defaults/appversions.json

@@ -0,0 +1,15 @@
+{
+  "clients": [
+    {
+      "clientId": "deltachat",
+      "sources": [
+        {
+          "sourceId": "gplay",
+          "versionInteger": 757,
+          "versionString": "2.59.1",
+          "downloadUrl": "https://github.com/deltachat/deltachat-android/releases/download/v2.59.1/deltachat-gplay-release-2.59.1.apk"
+        }
+      ]
+    }
+  ]
+}

chatmaild/src/chatmaild/doveauth.py

@@ -1,10 +1,17 @@
-import json
+"""Create chatmail addresses on first login.
+
+Dovecot only asks us about addresses it does not already find in the mailbox:
+the auth.lua we deploy with dovecot (cmdeploy/src/cmdeploy/dovecot/auth.lua.j2)
+verifies existing users itself against a mailbox password file,
+and HTTP-POSTs everything else to the /create endpoint implemented in this module.
+"""
+
 import logging
 import os
 import re
 import sys
-
-import filelock
+import threading
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 
 try:
     import crypt_r
@@ -12,8 +19,8 @@ except ImportError:
     import crypt as crypt_r
 
 from .config import Config, read_config
-from .dictproxy import DictProxy
 from .migrate_db import migrate_from_db_to_maildir
+from .syslimits import has_sufficient_resources
 
 NOCREATE_FILE = "/etc/chatmail-nocreate"
 VALID_LOCALPART_RE = re.compile(r"^[a-z0-9._-]+$")
@@ -63,107 +70,117 @@ def is_allowed_to_create(config: Config, user, cleartext_password) -> bool:
     return True
 
 
-def split_and_unescape(s):
-    """Split strings using double quote as a separator and backslash as escape character
-    into parts."""
-
-    out = ""
-    i = 0
-    while i < len(s):
-        c = s[i]
-        if c == "\\":
-            # Skip escape character.
-            i += 1
-
-            # This will raise IndexError if there is no character
-            # after escape character. This is expected
-            # as this is an invalid input.
-            out += s[i]
-        elif c == '"':
-            # Separator
-            yield out
-            out = ""
-        else:
-            out += c
-        i += 1
-    yield out
+def verify_password(stored, cleartext_password) -> bool:
+    if stored.startswith("{"):
+        stored = stored.split("}", 1)[1]
+    return crypt_r.crypt(cleartext_password, stored) == stored
 
 
-class AuthDictProxy(DictProxy):
+class DoveAuth:
     def __init__(self, config):
-        super().__init__()
         self.config = config
+        self.creation_lock = threading.Lock()
 
-    def handle_lookup(self, parts):
-        # Dovecot <2.3.17 has only one part,
-        # do not attempt to read any other parts for compatibility.
-        keyname = parts[0]
-
-        namespace, type, args = keyname.split("/", 2)
-        args = list(split_and_unescape(args))
-
+    def create_user(self, addr, cleartext_password) -> bool:
+        """Create the address, or verify the password if it exists already."""
         config = self.config
-        reply_command = "F"
-        res = ""
-        if namespace == "shared":
-            if type == "userdb":
-                user = args[0]
-                if user.endswith(f"@{config.mail_domain}"):
-                    res = self.lookup_userdb(user)
-                if res:
-                    reply_command = "O"
-                else:
-                    reply_command = "N"
-            elif type == "passdb":
-                user = args[1]
-                if user.endswith(f"@{config.mail_domain}"):
-                    res = self.lookup_passdb(user, cleartext_password=args[0])
-                if res:
-                    reply_command = "O"
-                else:
-                    reply_command = "N"
-        json_res = json.dumps(res) if res else ""
-        return f"{reply_command}{json_res}\n"
-
-    def handle_iterate(self, parts):
-        # example: I0\t0\tshared/userdb/
-        if parts[2] == "shared/userdb/":
-            result = "".join(
-                f"Oshared/userdb/{user}\t\n" for user in self.iter_userdb()
-            )
-            return f"{result}\n"
-
-    def iter_userdb(self) -> list:
-        """Get a list of all user addresses."""
-        return [x for x in os.listdir(self.config.mailboxes_dir) if "@" in x]
-
-    def lookup_userdb(self, addr):
-        return self.config.get_user(addr).get_userdb_dict()
-
-    def lookup_passdb(self, addr, cleartext_password):
-        user = self.config.get_user(addr)
-        userdata = user.get_userdb_dict()
-        if userdata:
-            return userdata
-        if not is_allowed_to_create(self.config, addr, cleartext_password):
-            return
-
-        lock = filelock.FileLock(str(user.password_path) + ".lock", timeout=5)
-        with lock:
-            userdata = user.get_userdb_dict()
-            if userdata:
-                return userdata
+        if not addr.endswith(f"@{config.mail_domain}"):
+            logging.warning("address not in mail domain: %r", addr)
+            return False
+        try:
+            user = config.get_user(addr)
+        except ValueError:
+            logging.warning("invalid address: %r", addr)
+            return False
+        with self.creation_lock:
+            passhash = user.get_password_hash()
+            if passhash is not None:
+                # a concurrent first login may have just created the address
+                return verify_password(passhash, cleartext_password)
+            if not is_allowed_to_create(config, addr, cleartext_password):
+                return False
+            if not has_sufficient_resources(config):
+                return False
             user.set_password(encrypt_password(cleartext_password))
-            print(f"Created address: {addr}", file=sys.stderr)
-        return user.get_userdb_dict()
+        # mtail counts created_accounts off this exact line
+        print(f"Created address: {addr}", file=sys.stderr)
+        return True
+
+
+class CreateHandler(BaseHTTPRequestHandler):
+    """Answer POST /create requests from dovecot's auth.lua, body `addr\\tpassword`.
+
+    The body must be UTF-8 and only the first tab separates the fields,
+    so a password may itself contain tabs.
+    Any non-UTF8 or \\0 bytes in the body fail the request.
+
+    Addresses are ASCII: dovecot refuses any login name outside its
+    auth_username_chars before auth.lua ever sees it.
+
+    Dovecot hands auth.lua the exact password bytes the client sent;
+    decoding and re-encoding UTF-8 is byte-identical,
+    so dovecot's password_verify later recomputes the same hash crypt() stores here.
+    """
+
+    protocol_version = "HTTP/1.1"  # dovecot's HTTP client reuses connections
+
+    max_body_len = 512  # an address and a password
+
+    def do_POST(self):
+        if self.path != "/create":
+            self.reply(404)
+            return
+        length = self.body_length()
+        if length is None:
+            self.reply(400)
+            return
+        body = self.rfile.read(length)
+        try:
+            addr, _, password = body.decode("utf-8").partition("\t")
+        except UnicodeDecodeError:
+            self.reply(400)
+            return
+        if "\0" in addr or "\0" in password:
+            self.reply(400)
+            return
+        self.reply(200 if self.server.doveauth.create_user(addr, password) else 403)
+
+    def body_length(self):
+        try:
+            length = int(self.headers["Content-Length"])
+        except (TypeError, ValueError):
+            return None
+        return length if 0 <= length <= self.max_body_len else None
+
+    def reply(self, status):
+        self.send_response(status)
+        self.send_header("Content-Length", "0")
+        if status != 200:
+            # Just close on any failure, as body might not be fully read.
+            # It's anyway cheap to re-establish http localhost without TLS.
+            self.send_header("Connection", "close")
+        self.end_headers()
+
+    def log_message(self, format, *args):
+        # the per-request access log would only duplicate our own stderr lines
+        pass
+
+
+class DoveAuthServer(ThreadingHTTPServer):
+    # a burst of first-time logins (e.g. from CI) must not overflow
+    # the accept queue, see https://github.com/chatmail/relay/issues/436
+    request_queue_size = 1000
+
+    def __init__(self, config, port):
+        super().__init__(("127.0.0.1", port), CreateHandler)
+        self.doveauth = DoveAuth(config)
 
 
 def main():
-    socket, cfgpath = sys.argv[1:]
+    (cfgpath,) = sys.argv[1:]
     config = read_config(cfgpath)
 
     migrate_from_db_to_maildir(config)
 
-    dictproxy = AuthDictProxy(config=config)
-
-    dictproxy.serve_forever_from_socket(socket)
+    server = DoveAuthServer(config, config.doveauth_http_port)
+    server.serve_forever()

chatmaild/src/chatmaild/expire.py

@@ -259,7 +259,7 @@ def daily_expire_main(args=None):
     args = parser.parse_args(args)
 
     config = read_config(args.chatmail_ini)
-    now = datetime.utcnow().timestamp()
+    now = time.time()
     if args.days:
         now = now - 86400 * int(args.days)
 

chatmaild/src/chatmaild/fsreport.py

@@ -27,6 +27,7 @@ to also write legacy metrics.py style output (default: /var/www/html/metrics):
 
 import os
 import tempfile
+import time
 from argparse import ArgumentParser
 from datetime import datetime
 
@@ -264,7 +265,7 @@ def main(args=None):
 
     config = read_config(args.chatmail_ini)
 
-    now = datetime.utcnow().timestamp()
+    now = time.time()
     if args.days:
         now = now - 86400 * int(args.days)
 

chatmaild/src/chatmaild/ini/chatmail.ini.f

@@ -3,9 +3,6 @@
 # mail domain (MUST be set to fully qualified chat mail domain)
 mail_domain = {mail_domain}
 
-# Where to deploy the relay - if unspecified, mail_domain will be used.
-ssh_host = localhost
-
 #
 # If you only do private test deploys, you don't need to modify any settings below
 #
@@ -45,6 +42,33 @@ ssh_host = localhost
 # minimum length a password must have
 #password_min_length = 9
 
+#
+# System resource limits
+#
+
+# The following three limits refuse creation of new addresses
+# while existing addresses keep working.
+# Rejections are logged by the doveauth service.
+
+# Maximum 1-minute load average, as reported by "uptime";
+# it counts processes waiting for disk I/O as well as for CPU.
+#max_load_1m = 5
+
+# Minimum memory available without swapping.
+#min_available_memory = 200M
+
+# Minimum free disk space on the file system holding the mailboxes.
+#min_free_disk_space = 1G
+
+# Maximum number of concurrent IMAP connections
+# (the Dovecot imap process limit).
+#max_imap_connections = 10000
+
+# Maximum number of concurrent SMTP connections
+# on each of the submission and smtps ports (the Postfix process limit).
+# A single client IP may use up to a fifth of this.
+#max_smtp_connections = 1000
+
 # Use externally managed TLS certificates instead of built-in acmetool.
 # Paths refer to files on the deployment server (not the build machine).
 # Both files must already exist before running cmdeploy.

chatmaild/src/chatmaild/metadata.py

@@ -1,8 +1,10 @@
+import json
 import logging
 import socket
 import sys
 import time
 from contextlib import contextmanager
+from importlib.resources import files
 
 from .config import read_config
 from .dictproxy import DictProxy
@@ -18,6 +20,18 @@ def turn_credentials(turn_socket_path):
             return file.readline().decode("utf-8").strip()
 
 
+def read_appversions(path):
+    try:
+        data = json.loads(path.read_bytes())
+    except FileNotFoundError:
+        return None
+    except (OSError, ValueError):
+        logging.exception(f"failed to read {path}")
+        return None
+    # the dict protocol is line-based, keep the value single-line
+    return json.dumps(data, separators=(",", ":"))
+
+
 def _is_valid_token_timestamp(timestamp, now):
     # Token if invalid after 90 days
     # or if the timestamp is in the future.
@@ -101,6 +115,7 @@ class MetadataDictProxy(DictProxy):
         self.iroh_relay = iroh_relay
         self.turn_hostname = turn_hostname
         self.turn_socket_path = turn_socket_path
+        self.appversions_path = files(__package__).joinpath("defaults/appversions.json")
 
     def handle_lookup(self, parts):
         # Lpriv/43f5f508a7ea0366dff30200c15250e3/devicetoken\tlkj123poi@c2.testrun.org
@@ -125,6 +140,9 @@ class MetadataDictProxy(DictProxy):
                         case "maxsmtprecipients":
                             # postfix default  (see "postconf smtpd_recipient_limit")
                             return "O1000\n"
+                        case "appversions":
+                            value = read_appversions(self.appversions_path)
+                            return f"O{value}\n" if value else "N\n"
 
         logging.warning(f"lookup ignored: {parts!r}")
         return "N\n"

chatmaild/src/chatmaild/syslimits.py

@@ -0,0 +1,32 @@
+"""Detect whether the system is at its limits."""
+
+import logging
+
+import psutil
+
+MB = 1024 * 1024
+
+
+def read_value(getter):
+    try:
+        return getter()
+    except Exception as e:
+        logging.warning("ignoring unreadable system limit: %s", e)
+        return None
+
+
+def has_sufficient_resources(config):
+    """Return False if load, memory or disk exceeds a configured limit."""
+    load = read_value(lambda: psutil.getloadavg()[0])
+    mem = read_value(lambda: psutil.virtual_memory().available // MB)
+    disk = read_value(lambda: psutil.disk_usage(str(config.mailboxes_dir)).free // MB)
+    if load is not None and load > config.max_load_1m:
+        msg = f"load avg {load:.2f} > {config.max_load_1m:.2f}"
+    elif mem is not None and mem < config.min_available_memory_mb:
+        msg = f"available memory {mem}MB < {config.min_available_memory_mb}MB"
+    elif disk is not None and disk < config.min_free_disk_space_mb:
+        msg = f"free disk {disk}MB < {config.min_free_disk_space_mb}MB"
+    else:
+        return True
+    logging.warning("registration rejected: %s", msg)
+    return False

chatmaild/src/chatmaild/tests/conftest.py

@@ -0,0 +1,3 @@
+"""Opt in to the chatmaild fixtures, which are not registered globally."""
+
+from chatmaild.tests.plugin import *  # noqa: F403

chatmaild/src/chatmaild/tests/plugin.py

@@ -20,6 +20,10 @@ def make_config(tmp_path):
         basedir.mkdir(parents=True, exist_ok=True)
         overrides = settings.copy() if settings else {}
         overrides["mailboxes_dir"] = str(basedir)
+        # permissive resource limits so tests never depend on host load/memory/disk
+        overrides.setdefault("max_load_1m", "99999")
+        overrides.setdefault("min_available_memory", "0")
+        overrides.setdefault("min_free_disk_space", "0")
         write_initial_config(inipath, mail_domain, overrides=overrides)
         return read_config(inipath)
 
@@ -37,22 +41,22 @@ def ipv4_config(make_config):
 
 
 @pytest.fixture
-def maildomain(example_config):
+def example_maildomain(example_config):
     return example_config.mail_domain
 
 
 @pytest.fixture
-def testaddr(maildomain):
-    return f"user.name@{maildomain}"
+def testaddr(example_maildomain):
+    return f"user.name@{example_maildomain}"
 
 
 @pytest.fixture
-def gencreds(maildomain):
+def example_gencreds(example_maildomain):
     count = itertools.count()
     next(count)
 
     def gen(domain=None):
-        domain = domain if domain else maildomain
+        domain = domain if domain else example_maildomain
         while 1:
             num = next(count)
             alphanumeric = "abcdefghijklmnopqrstuvwxyz1234567890"

chatmaild/src/chatmaild/tests/test_appversions.py

@@ -0,0 +1,96 @@
+import json
+
+import pytest
+
+from chatmaild.metadata import MetadataDictProxy
+
+ALLOWED_URL_PREFIXES = (
+    "https://github.com/deltachat/",
+    "https://download.delta.chat/",
+)
+
+
+def check_string(value):
+    assert isinstance(value, str), value
+    assert value
+
+
+def check_version_integer(value):
+    # core parses this as u32, see https://github.com/chatmail/core/pull/8557
+    assert isinstance(value, int) and not isinstance(value, bool), value
+    assert 0 <= value < 2**32, value
+
+
+def check_appversions(data):
+    """Verifies the file the way core parses it.
+
+    core deserializes into typed structs and drops the whole payload
+    of a relay if a single value has an unexpected type,
+    while missing or misspelled keys silently turn into defaults.
+    """
+    assert set(data) == {"clients"}, data
+    assert isinstance(data["clients"], list)
+    assert data["clients"]
+    client_ids = []
+    for client in data["clients"]:
+        assert set(client) == {"clientId", "sources"}, client
+        check_string(client["clientId"])
+        client_ids.append(client["clientId"])
+        assert isinstance(client["sources"], list)
+        assert client["sources"]
+        source_ids = []
+        for source in client["sources"]:
+            assert set(source) == {
+                "sourceId",
+                "versionInteger",
+                "versionString",
+                "downloadUrl",
+            }, source
+            check_string(source["sourceId"])
+            source_ids.append(source["sourceId"])
+            check_version_integer(source["versionInteger"])
+            check_string(source["versionString"])
+            check_string(source["downloadUrl"])
+            assert source["downloadUrl"].startswith(ALLOWED_URL_PREFIXES)
+        # core takes the first matching source, later duplicates never surface
+        assert len(set(source_ids)) == len(source_ids), source_ids
+    assert len(set(client_ids)) == len(client_ids), client_ids
+
+
+@pytest.fixture
+def appversions():
+    # check the file which chatmail-metadata actually serves
+    path = MetadataDictProxy(notifier=None, metadata=None).appversions_path
+    return json.loads(path.read_text())
+
+
+def test_appversions_schema(appversions):
+    check_appversions(appversions)
+
+
+@pytest.mark.parametrize("value", [True, -1, 2**32, "754", 754.0, None])
+def test_version_integer_rejected(appversions, value):
+    appversions["clients"][0]["sources"][0]["versionInteger"] = value
+    with pytest.raises(AssertionError):
+        check_appversions(appversions)
+
+
+@pytest.mark.parametrize("key", ["clientId", "sources"])
+def test_misspelled_client_key_rejected(appversions, key):
+    client = appversions["clients"][0]
+    client[key + "s"] = client.pop(key)
+    with pytest.raises(AssertionError):
+        check_appversions(appversions)
+
+
+def test_duplicate_source_id_rejected(appversions):
+    sources = appversions["clients"][0]["sources"]
+    sources.append(dict(sources[0]))
+    with pytest.raises(AssertionError):
+        check_appversions(appversions)
+
+
+def test_foreign_download_url_rejected(appversions):
+    appversions["clients"][0]["sources"][0]["downloadUrl"] = "https://example.org/x.apk"
+    with pytest.raises(AssertionError):
+        check_appversions(appversions)

chatmaild/src/chatmaild/tests/test_config.py

@@ -30,9 +30,9 @@ def test_read_config_ipv4(ipv4_config):
     assert ipv4_config.mail_domain == "[1.3.3.7]"
 
 
-def test_read_config_basic_using_defaults(tmp_path, maildomain):
+def test_read_config_basic_using_defaults(tmp_path, example_maildomain):
     inipath = tmp_path.joinpath("chatmail.ini")
-    inipath.write_text(f"[params]\nmail_domain = {maildomain}")
+    inipath.write_text(f"[params]\nmail_domain = {example_maildomain}")
     example_config = read_config(inipath)
     assert example_config.max_user_send_per_minute == 60
     assert example_config.filtermail_smtp_port_incoming == 10081
@@ -45,6 +45,8 @@ def test_read_config_basic_using_defaults(tmp_path, maildomain):
     assert example_config.username_min_length == 9
     assert example_config.username_max_length == 9
     assert example_config.password_min_length == 9
+    assert example_config.max_imap_connections == 10000
+    assert example_config.max_smtp_connections == 1000
     assert example_config._unused_keys == []
 
 

chatmaild/src/chatmaild/tests/test_delete_inactive_users.py

@@ -1,6 +1,6 @@
 import time
 
-from chatmaild.doveauth import AuthDictProxy
+from chatmaild.doveauth import DoveAuth
 from chatmaild.expire import daily_expire_main as main_expire
 
 
@@ -18,10 +18,10 @@ def test_login_timestamps(example_config):
 def test_delete_inactive_users(example_config):
     new = time.time()
     old = new - (example_config.delete_inactive_users_after * 86400) - 1
-    dictproxy = AuthDictProxy(example_config)
+    doveauth = DoveAuth(example_config)
 
     def create_user(addr, last_login):
-        dictproxy.lookup_passdb(addr, "q9mr3faue")
+        doveauth.create_user(addr, "q9mr3faue")
         user = example_config.get_user(addr)
         user.maildir.joinpath("cur").mkdir()
         user.maildir.joinpath("cur", "something").mkdir()

chatmaild/src/chatmaild/tests/test_doveauth.py

@@ -1,42 +1,37 @@
-import io
-import json
-import queue
+import http.client
 import threading
-import traceback
+from concurrent.futures import ThreadPoolExecutor
 
 import pytest
 
 import chatmaild.doveauth
 from chatmaild.doveauth import (
-    AuthDictProxy,
+    CreateHandler,
+    DoveAuth,
+    DoveAuthServer,
     is_allowed_to_create,
 )
 from chatmaild.newemail import create_newemail_dict
 
 
 @pytest.fixture
-def dictproxy(example_config):
-    return AuthDictProxy(config=example_config)
+def doveauth(example_config):
+    return DoveAuth(example_config)
 
 
-def test_basic(dictproxy, gencreds):
-    addr, password = gencreds()
-    dictproxy.lookup_passdb(addr, password)
-    data = dictproxy.lookup_userdb(addr)
-    assert data
-    data2 = dictproxy.lookup_passdb(addr, password)
-    assert data == data2
+def stored_hash(config, addr):
+    return config.get_user(addr).get_password_hash()
 
 
-def test_iterate_addresses(dictproxy):
-    addresses = []
+def test_basic(doveauth, example_config, example_gencreds):
+    addr, password = example_gencreds()
+    assert doveauth.create_user(addr, password)
+    passhash = stored_hash(example_config, addr)
+    assert passhash.startswith("{SHA512-CRYPT}")
 
-    for i in range(10):
-        addresses.append(f"asdf1234{i}@chat.example.org")
-        dictproxy.lookup_passdb(addresses[-1], "q9mr3faue")
-
-    res = dictproxy.iter_userdb()
-    assert set(res) == set(addresses)
+    # a second login verifies against the stored hash and rewrites nothing
+    assert doveauth.create_user(addr, password)
+    assert stored_hash(example_config, addr) == passhash
 
 
 def test_invalid_username_length(example_config):
@@ -53,75 +48,32 @@ def test_invalid_username_length(example_config):
     )
 
 
-def test_dont_overwrite_password_on_wrong_login(dictproxy):
-    """Test that logging in with a different password doesn't create a new user"""
-    res = dictproxy.lookup_passdb(
-        "newuser12@chat.example.org", "kajdlkajsldk12l3kj1983"
-    )
-    assert res["password"]
-    res2 = dictproxy.lookup_passdb("newuser12@chat.example.org", "kajdslqwe")
-    # this function always returns a password hash, which is actually compared by dovecot.
-    assert res["password"] == res2["password"]
+def test_dont_overwrite_password_on_wrong_login(doveauth, example_config):
+    addr = "newuser12@chat.example.org"
+    assert doveauth.create_user(addr, "kajdlkajsldk12l3kj1983")
+    passhash = stored_hash(example_config, addr)
+
+    assert not doveauth.create_user(addr, "kajdslqwe")
+    assert stored_hash(example_config, addr) == passhash
+
+    assert doveauth.create_user(addr, "kajdlkajsldk12l3kj1983")
+    assert stored_hash(example_config, addr) == passhash
 
 
-def test_nocreate_file(monkeypatch, tmpdir, dictproxy):
+def test_foreign_domain_is_refused(doveauth):
+    assert not doveauth.create_user("newuser12@evil.example.org", "qlwkejqlwe12")
+
+
+def test_nocreate_file(monkeypatch, tmpdir, doveauth, example_config):
     p = tmpdir.join("nocreate")
     p.write("")
     monkeypatch.setattr(chatmaild.doveauth, "NOCREATE_FILE", str(p))
-    dictproxy.lookup_passdb("newuser12@chat.example.org", "zequ0Aimuchoodaechik")
-    assert not dictproxy.lookup_userdb("newuser12@chat.example.org")
-
-
-def test_handle_dovecot_request(dictproxy):
-    transactions = {}
-    # Test that password can contain ", ', \ and /
-    msg = (
-        'Lshared/passdb/laksjdlaksjdlak\\\\sjdlk\\"12j\\\'3l1/k2j3123"'
-        "some42123@chat.example.org\tsome42123@chat.example.org"
-    )
-    res = dictproxy.handle_dovecot_request(msg, transactions)
-    assert res
-    assert res[0] == "O" and res.endswith("\n")
-    userdata = json.loads(res[1:].strip())
-    assert userdata["home"].endswith("chat.example.org/some42123@chat.example.org")
-    assert userdata["uid"] == userdata["gid"] == "vmail"
-    assert userdata["password"].startswith("{SHA512-CRYPT}")
-
-
-def test_handle_dovecot_protocol_hello_is_skipped(example_config, caplog):
-    dictproxy = AuthDictProxy(config=example_config)
-    rfile = io.BytesIO(b"H3\t2\t0\t\tauth\n")
-    wfile = io.BytesIO()
-    dictproxy.loop_forever(rfile, wfile)
-    assert wfile.getvalue() == b""
-    assert not caplog.messages
-
-
-def test_handle_dovecot_protocol_user_not_exists(example_config):
-    dictproxy = AuthDictProxy(config=example_config)
-    rfile = io.BytesIO(
-        b"H3\t2\t0\t\tauth\nLshared/userdb/foobar@chat.example.org\tfoobar@chat.example.org\n"
-    )
-    wfile = io.BytesIO()
-    dictproxy.loop_forever(rfile, wfile)
-    assert wfile.getvalue() == b"N\n"
-
-
-def test_handle_dovecot_protocol_iterate(gencreds, example_config):
-    dictproxy = AuthDictProxy(config=example_config)
-    dictproxy.lookup_passdb("asdf00000@chat.example.org", "q9mr3faue")
-    dictproxy.lookup_passdb("asdf11111@chat.example.org", "q9mr3faue")
-    rfile = io.BytesIO(b"H3\t2\t0\t\tauth\nI0\t0\tshared/userdb/")
-    wfile = io.BytesIO()
-    dictproxy.loop_forever(rfile, wfile)
-    lines = wfile.getvalue().decode("ascii").split("\n")
-    assert "Oshared/userdb/asdf00000@chat.example.org\t" in lines
-    assert "Oshared/userdb/asdf11111@chat.example.org\t" in lines
-    assert not lines[2]
+    addr = "newuser12@chat.example.org"
+    assert not doveauth.create_user(addr, "zequ0Aimuchoodaechik")
+    assert stored_hash(example_config, addr) is None
 
 
 def test_invalid_localpart_characters(make_config):
-    """Test that is_allowed_to_create rejects localparts with invalid characters."""
     config = make_config("chat.example.org", {"username_min_length": "3"})
     password = "zequ0Aimuchoodaechik"
     domain = config.mail_domain
@@ -141,64 +93,150 @@ def test_invalid_localpart_characters(make_config):
     assert not is_allowed_to_create(config, f"ab@cdef@{domain}", password)
     assert not is_allowed_to_create(config, f"abc/def@{domain}", password)
     assert not is_allowed_to_create(config, f"abc\\def@{domain}", password)
+    assert not is_allowed_to_create(config, f"üser123@{domain}", password)
 
 
-def test_concurrent_creation_same_account(dictproxy):
-    """Test that concurrent creation of the same account doesn't corrupt password."""
+def test_concurrent_creation_same_account(doveauth, example_config, capsys):
     addr = "racetest1@chat.example.org"
     password = "zequ0Aimuchoodaechik"
-    num_threads = 10
-    results = queue.Queue()
 
-    def create():
-        try:
-            res = dictproxy.lookup_passdb(addr, password)
-            results.put(("ok", res))
-        except Exception:
-            results.put(("err", traceback.format_exc()))
-
-    threads = [threading.Thread(target=create, daemon=True) for _ in range(num_threads)]
-    for t in threads:
-        t.start()
-    for t in threads:
-        t.join(timeout=10)
-
-    passwords_seen = set()
-    for _ in range(num_threads):
-        status, res = results.get()
-        if status == "err":
-            pytest.fail(f"concurrent creation failed\n{res}")
-        passwords_seen.add(res["password"])
+    def create(_):
+        ok = doveauth.create_user(addr, password)
+        return ok, stored_hash(example_config, addr)
 
+    with ThreadPoolExecutor(10) as pool:
+        results = list(pool.map(create, range(10)))
+    assert all(ok for ok, _ in results)
     # all threads must see the same password hash
-    assert len(passwords_seen) == 1
+    assert len({passhash for _, passhash in results}) == 1
+    assert capsys.readouterr().err.count("Created address:") == 1
 
 
-def test_50_concurrent_lookups_different_accounts(gencreds, dictproxy):
-    num_threads = 50
-    req_per_thread = 5
-    results = queue.Queue()
+def test_insufficient_resources_block_creation_not_existing_logins(
+    doveauth, example_gencreds, monkeypatch
+):
+    addr, password = example_gencreds()
+    assert doveauth.create_user(addr, password)
 
-    def lookup():
-        for i in range(req_per_thread):
-            addr, password = gencreds()
+    monkeypatch.setattr(
+        chatmaild.doveauth, "has_sufficient_resources", lambda config: False
+    )
+    newaddr, newpassword = example_gencreds()
+    assert not doveauth.create_user(newaddr, newpassword)
+    assert doveauth.create_user(addr, password)
+
+
+class TestHttpPost:
+    @pytest.fixture
+    def doveauth_server(self, example_config):
+        server = DoveAuthServer(example_config, port=0)
+        threading.Thread(target=server.serve_forever, daemon=True).start()
+        yield f"127.0.0.1:{server.server_address[1]}"
+        server.shutdown()
+        server.server_close()
+
+    @pytest.fixture
+    def post(self, doveauth_server):
+        def post(path, data):
+            conn = http.client.HTTPConnection(doveauth_server, timeout=10)
             try:
-                dictproxy.lookup_passdb(addr, password)
-            except Exception:
-                results.put(traceback.format_exc())
-            else:
-                results.put(None)
+                return self.post_on(conn, path, data).status
+            finally:
+                conn.close()
 
-    threads = []
-    for i in range(num_threads):
-        thread = threading.Thread(target=lookup, daemon=True)
-        threads.append(thread)
+        return post
 
-    print(f"created {num_threads} threads, starting them and waiting for results")
-    for thread in threads:
-        thread.start()
+    @pytest.fixture
+    def connection(self, doveauth_server):
+        """One kept-alive connection, which is all dovecot's HTTP client opens."""
+        conn = http.client.HTTPConnection(doveauth_server, timeout=10)
+        yield conn
+        conn.close()
 
-    for i in range(num_threads * req_per_thread):
-        res = results.get()
-        if res is not None:
-            pytest.fail(f"concurrent lookup failed\n{res}")
+    @staticmethod
+    def post_on(conn, path, data):
+        conn.request("POST", path, body=data)
+        resp = conn.getresponse()
+        resp.read()
+        return resp
+
+    def test_create_and_verify(self, post, example_config, example_gencreds):
+        addr, password = example_gencreds()
+        assert post("/create", f"{addr}\t{password}".encode()) == 200
+        assert stored_hash(example_config, addr).startswith("{SHA512-CRYPT}")
+
+        # second login with the same password verifies, a wrong one is refused
+        assert post("/create", f"{addr}\t{password}".encode()) == 200
+        assert post("/create", f"{addr}\twrong{password}".encode()) == 403
+
+    def test_password_special_chars_survive_transport(self, post, example_gencreds):
+        addr, _ = example_gencreds()
+        password = "laksjdlaksjdlak\\sjdlk\"12j'3l1/k2\tj3123"
+        body = f"{addr}\t{password}".encode()
+        assert post("/create", body) == 200
+        assert post("/create", body) == 200
+        assert post("/create", f"{addr}\totherpassword1".encode()) == 403
+
+    def test_password_must_be_utf8(self, post, example_gencreds):
+        addr, _ = example_gencreds()
+        assert post("/create", f"{addr}\tpässwort12".encode()) == 200
+        assert post("/create", addr.encode() + b"\tp\xe4sswort12") == 400
+
+    def test_nul_is_refused_before_crypt_sees_it(self, post, example_gencreds):
+        addr, _ = example_gencreds()
+        assert post("/create", f"{addr}\tpass\0word12".encode()) == 400
+        assert (
+            post("/create", "us\0er12345@chat.example.org\tlongenough1".encode()) == 400
+        )
+
+    def test_refused_creation(self, post, example_gencreds):
+        addr, _ = example_gencreds()
+        assert post("/create", f"{addr}\tshort".encode()) == 403
+        assert post("/create", b"not-an-address\tlongenoughpassword") == 403
+        body = "bürger123@chat.example.org\tlongenoughpw".encode()
+        assert post("/create", body) == 403
+        assert post("/create", b"") == 403
+
+    def test_body_length_limit(self, post, example_gencreds):
+        addr, _ = example_gencreds()
+        fill = CreateHandler.max_body_len - len(addr) - len("\t")
+        body = f"{addr}\t{'x' * fill}".encode()
+        assert len(body) == CreateHandler.max_body_len
+        assert post("/create", body) == 200
+
+        body = f"{addr}\t{'x' * (fill + 1)}".encode()
+        assert len(body) == CreateHandler.max_body_len + 1
+        assert post("/create", body) == 400
+
+    def test_connection_is_reused_across_200_replies(
+        self, connection, example_gencreds
+    ):
+        addr, password = example_gencreds()
+        body = f"{addr}\t{password}".encode()
+        # create, then verify the same password, on one connection
+        for _ in range(2):
+            resp = self.post_on(connection, "/create", body)
+            assert (resp.status, resp.will_close) == (200, False)
+
+    @pytest.mark.parametrize(
+        "path,data,status",
+        [
+            ("/other", b"not read", 404),
+            ("/create", b"x" * (CreateHandler.max_body_len + 1), 400),
+            ("/create", b"not-an-address\tlongenoughpassword", 403),
+        ],
+    )
+    def test_error_replies_close_the_connection(self, connection, path, data, status):
+        resp = self.post_on(connection, path, data)
+        assert (resp.status, resp.will_close) == (status, True)
+
+    @pytest.mark.parametrize("content_length", [None, "-1", "notanumber", "999999"])
+    def test_bad_content_length(self, connection, content_length):
+        # the fixture timeout turns a server that waits for the body into a failure
+        connection.putrequest("POST", "/create", skip_accept_encoding=True)
+        if content_length is not None:
+            connection.putheader("Content-Length", content_length)
+        connection.endheaders()
+        resp = connection.getresponse()
+        assert resp.status == 400
+        assert resp.will_close

chatmaild/src/chatmaild/tests/test_expire.py

@@ -3,7 +3,6 @@ import os
 import random
 import shutil
 import time
-from datetime import datetime
 from fnmatch import fnmatch
 from pathlib import Path
 
@@ -41,7 +40,7 @@ def fill_mbox(folderdir):
 
 
 def create_new_messages(basedir, relpaths, size=1000, days=0):
-    now = datetime.utcnow().timestamp()
+    now = time.time()
 
     for relpath in relpaths:
         msg_path = Path(basedir).joinpath(relpath)
@@ -112,9 +111,7 @@ def test_mbox_without_password(mbox1, example_config, capsys):
     mbox_rescan = MailboxStat(mbox1.basedir)
     assert mbox_rescan.last_login is None
 
-    exp = Expiry(
-        example_config, dry=False, now=datetime.now().timestamp(), verbose=False
-    )
+    exp = Expiry(example_config, dry=False, now=time.time(), verbose=False)
     exp.process_mailbox_stat(mbox_rescan)
     out, err = capsys.readouterr()
     assert "doesn't have last_login but isn't empty" in err
@@ -152,7 +149,7 @@ def test_report_mdir_filters_by_path(mbox1, example_config):
     """Test that Report with mdir='cur' only counts messages in cur/ subdirectory."""
     from chatmaild.fsreport import Report
 
-    now = datetime.utcnow().timestamp()
+    now = time.time()
 
     # Set password mtime to old enough so min_login_age check passes
     password = Path(mbox1.basedir).joinpath("password")

chatmaild/src/chatmaild/tests/test_lastlogin.py

@@ -1,6 +1,6 @@
 import time
 
-from chatmaild.doveauth import AuthDictProxy
+from chatmaild.doveauth import DoveAuth
 from chatmaild.lastlogin import (
     LastLoginDictProxy,
 )
@@ -9,8 +9,8 @@ from chatmaild.lastlogin import (
 def test_handle_dovecot_request_last_login(testaddr, example_config):
     dictproxy = LastLoginDictProxy(config=example_config)
 
-    authproxy = AuthDictProxy(config=example_config)
-    authproxy.lookup_passdb(testaddr, "1l2k3j1l2k3jl123")
+    doveauth = DoveAuth(example_config)
+    doveauth.create_user(testaddr, "1l2k3j1l2k3jl123")
 
     dictproxy_transactions = {}
 

chatmaild/src/chatmaild/tests/test_metadata.py

@@ -1,4 +1,5 @@
 import io
+import json
 import time
 
 import pytest
@@ -7,6 +8,7 @@ import requests
 from chatmaild.metadata import (
     Metadata,
     MetadataDictProxy,
+    read_appversions,
 )
 from chatmaild.notifier import (
     Notifier,
@@ -369,6 +371,32 @@ def test_iroh_relay(dictproxy):
     assert wfile.getvalue() == b"Ohttps://example.org/\n"
 
 
+def test_read_appversions(tmp_path):
+    path = tmp_path.joinpath("appversions.json")
+    assert read_appversions(path) is None
+
+    path.write_text('{\n  "clients": []\n}')
+    assert read_appversions(path) == '{"clients":[]}'
+
+    # the value travels as a single dict protocol line
+    path.write_text('{"clients": [{"clientId": "one\\ntwo"}]}')
+    assert read_appversions(path) == '{"clients":[{"clientId":"one\\ntwo"}]}'
+
+    path.write_text("bad json")
+    assert read_appversions(path) is None
+
+
+def test_appversions_lookup(dictproxy):
+    # the version information shipped with chatmaild is served as a single line
+    key = b"Lshared/0123/vendor/vendor.dovecot/pvt/server/vendor/deltachat/appversions"
+    key += b"\tuser@example.org"
+    rfile, wfile = io.BytesIO(b"H\n" + key), io.BytesIO()
+    dictproxy.loop_forever(rfile, wfile)
+    value = wfile.getvalue()
+    assert value.startswith(b"O") and value.endswith(b"\n")
+    assert json.loads(value[1:])["clients"]
+
+
 def test_legacy_token_migration(metadata, testaddr):
     with metadata.get_metadata_dict(testaddr).modify() as data:
         data[metadata.DEVICETOKEN_KEY] = ["oldtoken1", "oldtoken2"]

chatmaild/src/chatmaild/tests/test_migrate_db.py

@@ -63,7 +63,7 @@ def test_migration(tmp_path, example_config, caplog):
         user = example_config.get_user(path.name)
         if last_login:
             assert user.get_last_login_timestamp() == last_login
-        assert password == user.get_userdb_dict()["password"]
+        assert password == user.get_password_hash()
 
     assert not all
     assert not example_config.passdb_path.exists()

chatmaild/src/chatmaild/tests/test_newmail.py

@@ -48,7 +48,7 @@ def test_create_dclogin_url_ipv4(ipv4_config):
     assert addr in url
 
 
-def test_print_new_account(capsys, monkeypatch, maildomain, tmpdir, example_config):
+def test_print_new_account(capsys, monkeypatch, tmpdir, example_config):
     monkeypatch.setattr(chatmaild.newemail, "CONFIG_PATH", str(example_config._inipath))
     print_new_account()
     out, err = capsys.readouterr()

chatmaild/src/chatmaild/tests/test_syslimits.py

@@ -0,0 +1,45 @@
+import shutil
+
+import psutil
+
+from chatmaild.syslimits import has_sufficient_resources
+
+PERMISSIVE = {
+    "max_load_1m": "99999",
+    "min_available_memory": "0",
+    "min_free_disk_space": "0",
+}
+
+
+def test_rejects_constrained_system(make_config, caplog):
+    assert has_sufficient_resources(make_config("chat.example.org", PERMISSIVE))
+    for settings in (
+        {"max_load_1m": "-1.0"},
+        {"min_available_memory": "99999999G"},
+        {"min_free_disk_space": "99999999G"},
+    ):
+        config = make_config("chat.example.org", PERMISSIVE | settings)
+        caplog.clear()
+        assert not has_sufficient_resources(config), settings
+        assert "registration rejected" in caplog.text
+
+
+def test_unreadable_disk_does_not_reject(make_config, caplog):
+    config = make_config(
+        "chat.example.org", PERMISSIVE | {"min_free_disk_space": "99999999G"}
+    )
+    shutil.rmtree(config.mailboxes_dir)
+    assert has_sufficient_resources(config)
+    assert "ignoring" in caplog.text
+
+
+def test_one_unreadable_value_keeps_other_checks(make_config, monkeypatch, caplog):
+    def raise_error(*args):
+        raise psutil.Error("dud")
+
+    monkeypatch.setattr(psutil, "getloadavg", raise_error)
+    config = make_config(
+        "chat.example.org", PERMISSIVE | {"min_free_disk_space": "99999999G"}
+    )
+    assert not has_sufficient_resources(config)
+    assert "ignoring" in caplog.text

chatmaild/src/chatmaild/tests/test_user.py

@@ -8,28 +8,23 @@ def test_login_timestamp(testaddr, example_config):
     assert user.get_last_login_timestamp() == 86400 * 2
 
 
-def test_get_user_dict_not_set(testaddr, example_config, caplog):
+def test_get_password_hash_not_set(testaddr, example_config, caplog):
     user = example_config.get_user(testaddr)
     assert not caplog.records
-    assert user.get_userdb_dict() == {}
+    assert user.get_password_hash() is None
     assert len(caplog.records) == 0
 
     user.set_password("")
-    assert user.get_userdb_dict() == {}
+    assert user.get_password_hash() is None
     assert len(caplog.records) == 1
 
 
-def test_get_user_dict(make_config, tmp_path):
+def test_get_password_hash(make_config, tmp_path):
     config = make_config("something.testrun.org")
-    addr = "user1@something.org"
-    user = config.get_user(addr)
+    user = config.get_user("user1@something.org")
     enc_password = "l1k2j31lk2j3l1k23j123"
     user.set_password(enc_password)
-    data = user.get_userdb_dict()
-    assert addr in str(data["home"])
-    assert data["uid"] == "vmail"
-    assert data["gid"] == "vmail"
-    assert data["password"] == enc_password
+    assert user.get_password_hash() == enc_password
 
 
 def test_no_mailboxes_dir(testaddr, example_config, tmp_path):

chatmaild/src/chatmaild/user.py

@@ -21,20 +21,17 @@ class User:
     def can_track(self):
         return "@" in self.addr
 
-    def get_userdb_dict(self):
-        """Return a non-empty dovecot 'userdb' style dict
-        if the user has an existing non-empty password"""
+    def get_password_hash(self):
         try:
-            pw = self.password_path.read_text()
+            passhash = self.password_path.read_text()
         except FileNotFoundError:
-            return {}
+            return None
 
-        if not pw:
+        if not passhash:
             logging.error(f"password is empty for: {self.addr}")
-            return {}
+            return None
 
-        home = str(self.maildir)
-        return dict(addr=self.addr, home=home, uid=self.uid, gid=self.gid, password=pw)
+        return passhash
 
     def is_incoming_cleartext_ok(self):
         return not self.enforce_E2EE_path.exists()

cmdeploy/pyproject.toml

@@ -19,6 +19,8 @@ dependencies = [
   "pytest-xdist", 
   "execnet",
   "imap_tools",
+  "jinja2",
+  "lupa",
   "deltachat-rpc-client",
   "deltachat-rpc-server",
 ]
@@ -26,10 +28,6 @@ dependencies = [
 [project.scripts]
 cmdeploy = "cmdeploy.cmdeploy:main"
 
-[project.entry-points.pytest11]
-"chatmaild.testplugin" = "chatmaild.tests.plugin"
-"cmdeploy.testplugin" = "cmdeploy.tests.plugin"
-
 [tool.pytest.ini_options]
 addopts = "-v -ra --strict-markers"
 

cmdeploy/src/cmdeploy/__init__.py

@@ -0,0 +1 @@
+

cmdeploy/src/cmdeploy/acmetool/__init__.py

@@ -4,6 +4,8 @@ from ..basedeploy import Deployer
 
 
 class AcmetoolDeployer(Deployer):
+    bin_path = "/usr/bin/acmetool"
+
     def __init__(self, email, domains):
         self.domains = domains
         self.email = email
@@ -41,8 +43,12 @@ class AcmetoolDeployer(Deployer):
             domains=self.domains,
         )
 
-        self.ensure_systemd_unit("acmetool/acmetool-redirector.service")
-        self.ensure_systemd_unit("acmetool/acmetool-reconcile.service")
+        self.ensure_systemd_unit(
+            "acmetool/acmetool-redirector.service.j2", bin_path=self.bin_path
+        )
+        self.ensure_systemd_unit(
+            "acmetool/acmetool-reconcile.service.j2", bin_path=self.bin_path
+        )
         self.ensure_systemd_unit("acmetool/acmetool-reconcile.timer")
 
     def activate(self):
@@ -52,5 +58,5 @@ class AcmetoolDeployer(Deployer):
 
         server.shell(
             name=f"Reconcile certificates for: {', '.join(self.domains)}",
-            commands=["acmetool --batch --xlog.severity=debug reconcile"],
+            commands=[f"{self.bin_path} --batch --xlog.severity=debug reconcile"],
         )

cmdeploy/src/cmdeploy/acmetool/acmetool-reconcile.service.j2

@@ -4,5 +4,5 @@ After=network.target
 
 [Service]
 Type=oneshot
-ExecStart=/usr/bin/acmetool --batch reconcile
+ExecStart={{ bin_path }} --batch reconcile
 

cmdeploy/src/cmdeploy/acmetool/acmetool-redirector.service.j2

@@ -3,7 +3,7 @@ Description=acmetool HTTP redirector
 
 [Service]
 Type=notify
-ExecStart=/usr/bin/acmetool redirector --service.uid=daemon --bind=127.0.0.1:402
+ExecStart={{ bin_path }} redirector --service.uid=daemon --bind=127.0.0.1:402
 Restart=always
 RestartSec=30
 

cmdeploy/src/cmdeploy/acmetool/response-file.yaml.j2

@@ -1,2 +1,2 @@
 "acme-enter-email": "{{ email }}"
-"acme-agreement:https://letsencrypt.org/documents/LE-SA-v1.6-August-18-2025.pdf": true
+"acme-agreement:https://letsencrypt.org/documents/LE-SA-v1.8-July-06-2026.pdf": true

cmdeploy/src/cmdeploy/basedeploy.py

@@ -51,7 +51,7 @@ def get_resource(arg, pkg=__package__):
     return importlib.resources.files(pkg).joinpath(arg)
 
 
-def configure_remote_units(deployer, mail_domain, units) -> None:
+def configure_remote_units(deployer, mail_domain, units, **kwargs) -> None:
     remote_base_dir = "/usr/local/lib/chatmaild"
     remote_venv_dir = f"{remote_base_dir}/venv"
     remote_chatmail_inipath = f"{remote_base_dir}/chatmail.ini"
@@ -63,6 +63,7 @@ def configure_remote_units(deployer, mail_domain, units) -> None:
             config_path=remote_chatmail_inipath,
             remote_venv_dir=remote_venv_dir,
             mail_domain=mail_domain,
+            **kwargs,
         )
 
         basename = fn if "." in fn else f"{fn}.service"
@@ -166,7 +167,7 @@ class Deployer:
             return self.put_template(src, dest, **kwargs)
         return self.put_file(src, dest)
 
-    def put_file(self, src, dest, mode="644"):
+    def put_file(self, src, dest, mode="644", **kwargs):
         if isinstance(src, str):
             src = get_resource(src)
         res = files.put(
@@ -176,6 +177,7 @@ class Deployer:
             user="root",
             group="root",
             mode=mode,
+            **kwargs,
         )
 
         return self._update_restart_signals(dest, res)
@@ -225,7 +227,7 @@ class Deployer:
         res = files.directory(name=name, path=path, present=False, **kwargs)
         return self._update_restart_signals(path, res)
 
-    def download_executable(self, url, dest, sha256sum, extract=None):
+    def download_executable(self, url, dest, sha256sum, extract=None, mode="755"):
         existing = host.get_fact(Sha256File, dest)
         if existing == sha256sum:
             return
@@ -242,7 +244,7 @@ class Deployer:
                 f"({dl_cmd}"
                 f" && echo '{sha256sum}  {tmp}' | sha256sum -c"
                 f" && mv {tmp} {dest})",
-                f"chmod 755 {dest}",
+                f"chmod {mode} {dest}",
             ],
         )
         self.need_restart = True

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -96,7 +96,7 @@ def _warn_unused_settings(unused_keys, out):
 def run_cmd(args, out):
     """Deploy chatmail services on the remote server."""
 
-    ssh_host = args.ssh_host if args.ssh_host else args.config.ssh_host
+    ssh_host = args.ssh_host if args.ssh_host else args.config.mail_domain_bare
     sshexec = get_sshexec(ssh_host)
     require_iroh = args.config.enable_iroh_relay
     strict_tls = args.config.tls_cert_mode == "acme"
@@ -116,7 +116,7 @@ def run_cmd(args, out):
     pyinf = "pyinfra --dry" if args.dry_run else "pyinfra"
 
     cmd = f"{pyinf} --ssh-user root {ssh_host} {deploy_path} -y"
-    if ssh_host in ["localhost", "@local"]:
+    if ssh_host == "localhost":
         cmd = f"{pyinf} @local {deploy_path} -y"
 
     if version.parse(pyinfra.__version__) < version.parse("3"):
@@ -158,7 +158,7 @@ def dns_cmd(args, out):
         ipv4 = args.config.ipv4_relay
         print(f"[WARNING] {ipv4} is not a domain, skipping DNS checks.")
         return 0
-    ssh_host = args.ssh_host if args.ssh_host else args.config.ssh_host
+    ssh_host = args.ssh_host if args.ssh_host else args.config.mail_domain
     sshexec = get_sshexec(ssh_host, verbose=args.verbose)
     tls_cert_mode = args.config.tls_cert_mode
     strict_tls = tls_cert_mode == "acme"
@@ -195,7 +195,7 @@ def status_cmd_options(parser):
 def status_cmd(args, out):
     """Display status for online chatmail instance."""
 
-    ssh_host = args.ssh_host if args.ssh_host else args.config.ssh_host
+    ssh_host = args.ssh_host if args.ssh_host else args.config.mail_domain_bare
     sshexec = get_sshexec(ssh_host, verbose=args.verbose)
 
     out.green(f"chatmail domain: {args.config.mail_domain}")

cmdeploy/src/cmdeploy/deployers.py

@@ -33,6 +33,7 @@ from .filtermail.deployer import FiltermailDeployer
 from .mtail.deployer import MtailDeployer
 from .nginx.deployer import NginxDeployer
 from .opendkim.deployer import OpendkimDeployer
+from .pins import IROH_ARTIFACTS, TURN_ARTIFACTS
 from .postfix.deployer import PostfixDeployer
 from .selfsigned.deployer import SelfSignedTlsDeployer
 from .www import build_webpages, find_merge_conflict, get_paths
@@ -138,9 +139,22 @@ class UnboundDeployer(Deployer):
         # On an IPv4-only system, if unbound is started but not configured,
         # it causes subsequent steps to fail to resolve hosts.
         with blocked_service_startup():
+            # dns-root-data is an optional package
+            # that contains /usr/share/dns/root.key
+            #
+            # This file is copied into /var/lib/unbound/root.key
+            # at the start of "unbound" systemd unit
+            # by /usr/libexec/unbound-helper shell script
+            # from the "unbound" package as of version 1.17.1-2+deb12u4
+            #
+            # The same /var/lib/unbound/root.key can be retrieved directly
+            # following the procedure from
+            # <https://www.rfc-editor.org/info/rfc7958/#section-3.1>
+            # with "unbound-anchor -a /var/lib/unbound/root.key"
+            # We don't install and use "unbound-anchor".
             apt.packages(
                 name="Install unbound",
-                packages=["unbound", "unbound-anchor", "dnsutils"],
+                packages=["unbound", "dns-root-data", "dnsutils"],
             )
 
     def configure(self):
@@ -164,12 +178,7 @@ class UnboundDeployer(Deployer):
         self.put_file(
             src=BytesIO(b"nameserver 127.0.0.1\nnameserver 9.9.9.9\n"),
             dest="/etc/resolv.conf",
-        )
-        server.shell(
-            name="Generate root keys for validating DNSSEC",
-            commands=[
-                "unbound-anchor -a /var/lib/unbound/root.key || true",
-            ],
+            force=True,
         )
         self.ensure_directory(
             path="/etc/unbound/unbound.conf.d",
@@ -245,6 +254,13 @@ class LegacyRemoveDeployer(Deployer):
     def install(self):
         apt.packages(name="Remove rspamd", packages="rspamd", present=False)
 
+        # unbound-anchor was used to download /var/lib/unbound/root.key
+        # It is replaced by dns-root-data which contains /usr/share/dns/root.key.
+        # unbound systemd unit copies /usr/share/dns/root.key
+        # into /var/lib/unbound/root.key automatically on start
+        # as long as /usr/share/dns/root.key is present.
+        apt.packages(name="Remove unbound-anchor", packages="unbound-anchor", present=False)
+
         # remove historic expunge script
         # which is now implemented through a systemd timer (chatmail-expire)
         self.remove_file("/etc/cron.d/expunge")
@@ -286,55 +302,48 @@ def check_config(config):
 
 
 class TurnDeployer(Deployer):
+    bin_path = "/usr/local/bin/chatmail-turn"
+
     def __init__(self, mail_domain):
         self.mail_domain = mail_domain
         self.units = ["turnserver"]
 
     def install(self):
-        (url, sha256sum) = {
-            "x86_64": (
-                "https://github.com/chatmail/chatmail-turn/releases/download/v0.4/chatmail-turn-x86_64-linux",
-                "1ec1f5c50122165e858a5a91bcba9037a28aa8cb8b64b8db570aa457c6141a8a",
-            ),
-            "aarch64": (
-                "https://github.com/chatmail/chatmail-turn/releases/download/v0.4/chatmail-turn-aarch64-linux",
-                "0fb3e792419494e21ecad536464929dba706bb2c88884ed8f1788141d26fc756",
-            ),
-        }[host.get_fact(facts.server.Arch)]
-        self.download_executable(url, "/usr/local/bin/chatmail-turn", sha256sum)
+        (url, sha256sum) = TURN_ARTIFACTS[host.get_fact(facts.server.Arch)]
+        self.download_executable(url, self.bin_path, sha256sum)
 
     def configure(self):
-        configure_remote_units(self, self.mail_domain, self.units)
+        configure_remote_units(
+            self, self.mail_domain, self.units, bin_path=self.bin_path
+        )
 
     def activate(self):
         activate_remote_units(self, self.units)
 
 
 class IrohDeployer(Deployer):
+    bin_path = "/usr/local/bin/iroh-relay"
+    config_path = "/etc/iroh-relay.toml"
+
     def __init__(self, enable_iroh_relay):
         self.enable_iroh_relay = enable_iroh_relay
 
     def install(self):
-        (url, sha256sum) = {
-            "x86_64": (
-                "https://github.com/n0-computer/iroh/releases/download/v0.35.0/iroh-relay-v0.35.0-x86_64-unknown-linux-musl.tar.gz",
-                "45c81199dbd70f8c4c30fef7f3b9727ca6e3cea8f2831333eeaf8aa71bf0fac1",
-            ),
-            "aarch64": (
-                "https://github.com/n0-computer/iroh/releases/download/v0.35.0/iroh-relay-v0.35.0-aarch64-unknown-linux-musl.tar.gz",
-                "f8ef27631fac213b3ef668d02acd5b3e215292746a3fc71d90c63115446008b1",
-            ),
-        }[host.get_fact(facts.server.Arch)]
+        (url, sha256sum) = IROH_ARTIFACTS[host.get_fact(facts.server.Arch)]
         self.download_executable(
             url,
-            "/usr/local/bin/iroh-relay",
+            self.bin_path,
             sha256sum,
             extract="gunzip | tar -xf - ./iroh-relay -O",
         )
 
     def configure(self):
-        self.ensure_systemd_unit("iroh-relay.service")
-        self.put_file("iroh-relay.toml", "/etc/iroh-relay.toml")
+        self.ensure_systemd_unit(
+            "iroh-relay.service.j2",
+            bin_path=self.bin_path,
+            config_path=self.config_path,
+        )
+        self.put_file("iroh-relay.toml", self.config_path)
 
     def activate(self):
         self.ensure_service(
@@ -355,6 +364,8 @@ class ChatmailVenvDeployer(Deployer):
     def __init__(self, config):
         self.config = config
         self.units = (
+            # doveauth must restart when chatmaild/ini file changes
+            "doveauth",
             "chatmail-metadata",
             "lastlogin",
             "chatmail-expire",
@@ -503,10 +514,10 @@ def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -
             ("nginx", 443),
             (["master", "smtpd"], 465),
             (["master", "smtpd"], 587),
-            (["imap-login", "dovecot"], 993),
+            (["dovecot", "imap-login"], 993),
             ("iroh-relay", 3340),
             ("mtail", 3903),
-            ("stats", 3904),
+            (["dovecot", "stats"], 3904),
             ("nginx", 8443),
             (["master", "smtpd"], config.postfix_reinject_port),
             (["master", "smtpd"], config.postfix_reinject_port_incoming),

cmdeploy/src/cmdeploy/dovecot/auth.conf

@@ -1,12 +0,0 @@
-uri = proxy:/run/doveauth/doveauth.socket:auth
-iterate_disable = no
-iterate_prefix = userdb/
-
-default_pass_scheme = plain
-# %E escapes characters " (double quote), ' (single quote) and \ (backslash) with \ (backslash).
-# See <https://doc.dovecot.org/2.3/configuration_manual/config_file/config_variables/#modifiers>
-# for documentation.
-#
-# We escape user-provided input and use double quote as a separator.
-password_key = passdb/%Ew"%Eu
-user_key = userdb/%Eu

cmdeploy/src/cmdeploy/dovecot/auth.lua.j2

@@ -0,0 +1,68 @@
+-- Existing addresses are served from the maildir directly.
+-- Unknown ones are offered to doveauth, which owns the creation policy.
+local mailboxes_dir = "{{ config.mailboxes_dir }}"
+local domain_suffix = "@{{ config.mail_domain }}"
+local create_url = "http://127.0.0.1:{{ config.doveauth_http_port }}/create"
+
+local http_client
+
+local function is_ours(user)
+  return user:sub(-#domain_suffix) == domain_suffix
+     and not user:find("/", 1, true)
+end
+
+local function password_hash(user)
+  local fh = io.open(mailboxes_dir .. "/" .. user .. "/password", "r")
+  if not fh then
+    return nil
+  end
+  local hash, rest = fh:read("l", "a")
+  fh:close()
+  if hash == nil or hash == "" or rest ~= "" then
+    return nil
+  end
+  return hash
+end
+
+local function userdb_fields(user)
+  return {home = mailboxes_dir .. "/" .. user, uid = "vmail", gid = "vmail"}
+end
+
+local function create(user, password)
+  local request = http_client:request({url = create_url, method = "POST"})
+  request:set_payload(user .. "\t" .. password)
+  return request:submit():status()
+end
+
+-- Entry points called by dovecot
+
+function script_init()
+  http_client = dovecot.http.client({request_timeout_msecs = 5000, max_attempts = 1})
+  return 0
+end
+
+function auth_userdb_lookup(req)
+  if not is_ours(req.user) or password_hash(req.user) == nil then
+    return dovecot.auth.USERDB_RESULT_USER_UNKNOWN, {}
+  end
+  return dovecot.auth.USERDB_RESULT_OK, userdb_fields(req.user)
+end
+
+function auth_password_verify(req, password)
+  if not is_ours(req.user) then
+    return dovecot.auth.PASSDB_RESULT_USER_UNKNOWN, {}
+  end
+  local hash = password_hash(req.user)
+  if hash == nil then
+    -- doveauth refuses with 4xx; dovecot reports its own failures as 9000 and up
+    local status = create(req.user, password)
+    if status >= 500 then
+      return dovecot.auth.PASSDB_RESULT_INTERNAL_FAILURE, {}
+    elseif status ~= 200 then
+      return dovecot.auth.PASSDB_RESULT_USER_UNKNOWN, {}
+    end
+  elseif req:password_verify(hash, password) ~= 1 then
+    return dovecot.auth.PASSDB_RESULT_PASSWORD_MISMATCH, {}
+  end
+  return dovecot.auth.PASSDB_RESULT_OK, userdb_fields(req.user)
+end

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -14,18 +14,9 @@ from cmdeploy.basedeploy import (
     configure_remote_units,
     is_in_container,
 )
+from cmdeploy.pins import DOVECOT_SHA256, DOVECOT_VERSION
 
-DOVECOT_ARCHIVE_VERSION = "2.3.21+dfsg1-3"
-DOVECOT_PACKAGE_VERSION = f"1:{DOVECOT_ARCHIVE_VERSION}"
-
-DOVECOT_SHA256 = {
-    ("core", "amd64"): "dd060706f52a306fa863d874717210b9fe10536c824afe1790eec247ded5b27d",
-    ("core", "arm64"): "e7548e8a82929722e973629ecc40fcfa886894cef3db88f23535149e7f730dc9",
-    ("imapd", "amd64"): "8d8dc6fc00bbb6cdb25d345844f41ce2f1c53f764b79a838eb2a03103eebfa86",
-    ("imapd", "arm64"): "178fa877ddd5df9930e8308b518f4b07df10e759050725f8217a0c1fb3fd707f",
-    ("lmtpd", "amd64"): "2f69ba5e35363de50962d42cccbfe4ed8495265044e244007d7ccddad77513ab",
-    ("lmtpd", "arm64"): "89f52fb36524f5877a177dff4a713ba771fd3f91f22ed0af7238d495e143b38f",
-}
+DOVECOT_PACKAGE_VERSION = f"1:{DOVECOT_VERSION}"
 
 
 class DovecotDeployer(Deployer):
@@ -34,13 +25,13 @@ class DovecotDeployer(Deployer):
     def __init__(self, config, disable_mail):
         self.config = config
         self.disable_mail = disable_mail
-        self.units = ["doveauth"]
+        self.units = []
 
     def install(self):
         arch = host.get_fact(Arch)
         with blocked_service_startup():
             debs = []
-            for pkg in ("core", "imapd", "lmtpd"):
+            for pkg in ("core", "imapd", "lmtpd", "auth-lua"):
                 deb, changed = _download_dovecot_package(pkg, arch)
                 self.need_restart |= changed
                 if deb:
@@ -117,7 +108,7 @@ def _download_dovecot_package(package: str, arch: str) -> tuple[str | None, bool
     if DOVECOT_PACKAGE_VERSION in installed_versions:
         return None, False
 
-    url_version = DOVECOT_ARCHIVE_VERSION.replace("+", "%2B")
+    url_version = DOVECOT_VERSION.replace("+", "%2B")
     deb_base = f"{pkg_name}_{url_version}_{arch}.deb"
     primary_url = f"https://download.delta.chat/dovecot/{deb_base}"
     fallback_url = f"https://github.com/chatmail/dovecot/releases/download/upstream%2F{url_version}/{deb_base}"
@@ -143,7 +134,8 @@ def _configure_dovecot(deployer, config: Config, debug: bool = False):
         debug=debug,
         disable_ipv6=config.disable_ipv6,
     )
-    deployer.put_file("dovecot/auth.conf", "/etc/dovecot/auth.conf")
+    deployer.put_template("dovecot/auth.lua.j2", "/etc/dovecot/auth.lua", config=config)
+    deployer.remove_file("/etc/dovecot/auth.conf")
     deployer.put_file(
         "dovecot/push_notification.lua", "/etc/dovecot/push_notification.lua"
     )

cmdeploy/src/cmdeploy/dovecot/dovecot.conf.j2

@@ -37,11 +37,15 @@ default_client_limit = 20000
 # the following warning will be logged:
 #   Warning: service(imap): process_limit (1024) reached, client connections are being dropped
 service imap {
-  process_limit = 50000
+  process_limit = {{ config.max_imap_connections }}
 }
 
-mail_server_admin = mailto:root@{{ config.mail_domain }}
-mail_server_comment = Chatmail server
+{% if config.privacy_mail %}
+# Advertised to clients as IMAP METADATA /shared/admin (RFC 5464).
+# The privacy_mail contact from chatmail.ini is used because it is
+# the only address set by an operator.
+mail_server_admin = mailto:{{ config.privacy_mail }}
+{% endif %}
 
 # `zlib` enables compressing messages stored in the maildir.
 # See
@@ -57,12 +61,12 @@ imap_capability = +XDELTAPUSH XCHATMAIL
 
 # Authentication for system users.
 passdb {
-  driver = dict
-  args = /etc/dovecot/auth.conf
+  driver = lua
+  args = file=/etc/dovecot/auth.lua blocking=yes
 }
 userdb {
-  driver = dict
-  args = /etc/dovecot/auth.conf
+  driver = lua
+  args = file=/etc/dovecot/auth.lua blocking=yes
 }
 ##
 ## Mailbox locations and namespaces

cmdeploy/src/cmdeploy/filtermail/deployer.py

@@ -3,6 +3,7 @@ import os
 from pyinfra import facts, host
 
 from cmdeploy.basedeploy import Deployer
+from cmdeploy.pins import FILTERMAIL_ARTIFACTS
 
 
 class FiltermailDeployer(Deployer):
@@ -20,11 +21,7 @@ class FiltermailDeployer(Deployer):
             return
 
         arch = host.get_fact(facts.server.Arch)
-        url = f"https://github.com/chatmail/filtermail/releases/download/v0.7.0/filtermail-{arch}"
-        sha256sum = {
-            "x86_64": "451f295a85b3b12dbb0f89e18ec319f742ee46dec218f20f7923bfb017a248bd",
-            "aarch64": "6833061b2a2028264fdeb32f0a6123e1ff73de57dace125364016300b748452e",
-        }[arch]
+        url, sha256sum = FILTERMAIL_ARTIFACTS[arch]
         self.download_executable(url, self.bin_path, sha256sum)
 
     def configure(self):

cmdeploy/src/cmdeploy/iroh-relay.service.j2

@@ -2,7 +2,7 @@
 Description=Iroh relay
 
 [Service]
-ExecStart=/usr/local/bin/iroh-relay --config-path /etc/iroh-relay.toml
+ExecStart={{ bin_path }} --config-path {{ config_path }}
 Restart=on-failure
 RestartSec=5s
 User=iroh

cmdeploy/src/cmdeploy/mtail/delivered_mail.mtail

@@ -28,6 +28,13 @@ counter created_nonci_accounts
   }
 }
 
+# doveauth refusing new addresses because a chatmail.ini
+# system resource limit is exceeded.
+counter rejected_registrations
+/registration rejected: / {
+  rejected_registrations++
+}
+
 counter postfix_timeouts
 /timeout after DATA/ {
   postfix_timeouts++
@@ -73,6 +80,11 @@ counter incoming_unencrypted_mail_count
   filtered_incoming_mail_count++
 }
 
+counter incoming_mailer_daemon_mail_count
+/Incoming: Filtering mailer-daemon message from/ {
+  incoming_mailer_daemon_mail_count++
+  filtered_incoming_mail_count++
+}
 
 counter rejected_unencrypted_mail_count
 /Rejected unencrypted mail/ {

cmdeploy/src/cmdeploy/mtail/deployer.py

@@ -1,10 +1,14 @@
 from pyinfra import facts, host
-from pyinfra.operations import apt
+from pyinfra.operations import apt, server
 
 from cmdeploy.basedeploy import Deployer
+from cmdeploy.pins import FILTERMAIL_ARTIFACTS, MTAIL_ARTIFACTS
 
 
 class MtailDeployer(Deployer):
+    bin_path = "/usr/local/bin/mtail"
+    progs_dir = "/etc/mtail"
+
     def __init__(self, mtail_address):
         self.mtail_address = mtail_address
 
@@ -12,19 +16,10 @@ class MtailDeployer(Deployer):
         # Uninstall mtail package to install a static binary.
         apt.packages(name="Uninstall mtail", packages=["mtail"], present=False)
 
-        (url, sha256sum) = {
-            "x86_64": (
-                "https://github.com/google/mtail/releases/download/v3.0.8/mtail_3.0.8_linux_amd64.tar.gz",
-                "d55cb601049c5e61eabab29998dbbcea95d480e5448544f9470337ba2eea882e",
-            ),
-            "aarch64": (
-                "https://github.com/google/mtail/releases/download/v3.0.8/mtail_3.0.8_linux_arm64.tar.gz",
-                "f748db8ad2a1e0b63684d4c8868cf6a373a20f7e6922e5ece601fff0ee00eb1a",
-            ),
-        }[host.get_fact(facts.server.Arch)]
+        (url, sha256sum) = MTAIL_ARTIFACTS[host.get_fact(facts.server.Arch)]
         self.download_executable(
             url,
-            "/usr/local/bin/mtail",
+            self.bin_path,
             sha256sum,
             extract="gunzip | tar -xf - mtail -O",
         )
@@ -36,8 +31,31 @@ class MtailDeployer(Deployer):
             "mtail/mtail.service.j2",
             address=self.mtail_address or "127.0.0.1",
             port=3903,
+            bin_path=self.bin_path,
+            progs_dir=self.progs_dir,
         )
-        self.put_file("mtail/delivered_mail.mtail", "/etc/mtail/delivered_mail.mtail")
+        if self.mtail_address:
+            self.put_file(
+                "mtail/delivered_mail.mtail", f"{self.progs_dir}/delivered_mail.mtail"
+            )
+            url, sha256sum = FILTERMAIL_ARTIFACTS['mtail']
+            self.download_executable(
+                url,
+                f"{self.progs_dir}/filtermail.mtail",
+                sha256sum,
+                mode="644",
+            )
+            if self.need_restart:
+                # Check if all installed mtail rules compile or fail early
+                # --one_shot to exit, --port 0 to not clash with running mtail.
+                server.shell(
+                    name="Validate mtail programs",
+                    commands=[
+                        f"timeout 30 {self.bin_path} --compile_only --one_shot"
+                        f" --progs {self.progs_dir} --logs /dev/null"
+                        " --address 127.0.0.1 --port 0"
+                    ],
+                )
 
     def activate(self):
         active = bool(self.mtail_address)

cmdeploy/src/cmdeploy/mtail/mtail.service.j2

@@ -5,7 +5,7 @@ Wants=network-online.target
 
 [Service]
 Type=simple
-ExecStart=/bin/sh -c "journalctl -f -o short-iso -n 0 | /usr/local/bin/mtail --address={{ address }} --port={{ port }} --progs /etc/mtail --logtostderr --logs -"
+ExecStart=/bin/sh -c "journalctl -f -o short-iso -n 0 | {{ bin_path }} --address={{ address }} --port={{ port }} --progs {{ progs_dir }} --logtostderr --logs -"
 Restart=on-failure
 RestartSec=2s
 

cmdeploy/src/cmdeploy/nginx/nginx.conf.j2

@@ -128,7 +128,10 @@ http {
                         proxy_set_header Connection "upgrade";
                 }
 
-		location /relay/probe {
+		# Endpoints Iroh uses for net_report probes and that clients
+		# probe to tell whether this relay works. Both paths are served
+		# by iroh-relay 0.35 and by the 1.0 line.
+		location /ping {
                         proxy_pass http://127.0.0.1:3340;
                         proxy_http_version 1.1;
 		}

cmdeploy/src/cmdeploy/pins.py

@@ -0,0 +1,64 @@
+"""Versions, hashes, and download URLs for pre-built artifacts fetched during deploy."""
+
+FILTERMAIL_VERSION = "v0.7.5"
+FILTERMAIL_ARTIFACTS = {
+    "x86_64": (
+        f"https://github.com/chatmail/filtermail/releases/download/{FILTERMAIL_VERSION}/filtermail-x86_64",
+        "cd744e910d1778ff017650123d6a9c941c9b5fee244364bb48babf27be037f55",
+    ),
+    "aarch64": (
+        f"https://github.com/chatmail/filtermail/releases/download/{FILTERMAIL_VERSION}/filtermail-aarch64",
+        "8d45b582193c0aee1dffc2ef6c424c0b6c93d9efc6e939531cde12dc9cc1a1a2",
+    ),
+    "mtail": (
+        f"https://raw.githubusercontent.com/chatmail/filtermail/{FILTERMAIL_VERSION}/contrib/filtermail.mtail",
+        "948f688bb89ad47e6eb0fc8fa107e201a689f5adc264ff926be487a2a8562b51",
+    ),
+}
+
+MTAIL_VERSION = "3.4.9"
+MTAIL_ARTIFACTS = {
+    "x86_64": (
+        f"https://github.com/jaqx0r/mtail/releases/download/v{MTAIL_VERSION}/mtail_{MTAIL_VERSION}_linux_amd64.tar.gz",
+        "55f64a87f71955bb871c724b4aadf19fe9d854e6327196919c7fe44943427eab",
+    ),
+    "aarch64": (
+        f"https://github.com/jaqx0r/mtail/releases/download/v{MTAIL_VERSION}/mtail_{MTAIL_VERSION}_linux_arm64.tar.gz",
+        "e0a2b66b372ca257d7daeb7ba10f9233a2192a1f9057618fccc6be5c854a2a3c",
+    ),
+}
+
+DOVECOT_VERSION = "2.3.21+dfsg1-3"
+DOVECOT_SHA256 = {
+    ("core", "amd64"): "dd060706f52a306fa863d874717210b9fe10536c824afe1790eec247ded5b27d",
+    ("core", "arm64"): "e7548e8a82929722e973629ecc40fcfa886894cef3db88f23535149e7f730dc9",
+    ("imapd", "amd64"): "8d8dc6fc00bbb6cdb25d345844f41ce2f1c53f764b79a838eb2a03103eebfa86",
+    ("imapd", "arm64"): "178fa877ddd5df9930e8308b518f4b07df10e759050725f8217a0c1fb3fd707f",
+    ("lmtpd", "amd64"): "2f69ba5e35363de50962d42cccbfe4ed8495265044e244007d7ccddad77513ab",
+    ("lmtpd", "arm64"): "89f52fb36524f5877a177dff4a713ba771fd3f91f22ed0af7238d495e143b38f",
+    ("auth-lua", "amd64"): "d724f37712faba52e177153114af1831e54da555c57c6474c05f96f176176ce4",
+    ("auth-lua", "arm64"): "7272768e20de148c35891d99cd60205acbe7e732b056caf0a83e8194d49136e6",
+}
+TURN_VERSION = "v0.4"
+TURN_ARTIFACTS = {
+    "x86_64": (
+        f"https://github.com/chatmail/chatmail-turn/releases/download/{TURN_VERSION}/chatmail-turn-x86_64-linux",
+        "1ec1f5c50122165e858a5a91bcba9037a28aa8cb8b64b8db570aa457c6141a8a",
+    ),
+    "aarch64": (
+        f"https://github.com/chatmail/chatmail-turn/releases/download/{TURN_VERSION}/chatmail-turn-aarch64-linux",
+        "0fb3e792419494e21ecad536464929dba706bb2c88884ed8f1788141d26fc756",
+    ),
+}
+
+IROH_VERSION = "v0.35.0"
+IROH_ARTIFACTS = {
+    "x86_64": (
+        f"https://github.com/n0-computer/iroh/releases/download/{IROH_VERSION}/iroh-relay-{IROH_VERSION}-x86_64-unknown-linux-musl.tar.gz",
+        "45c81199dbd70f8c4c30fef7f3b9727ca6e3cea8f2831333eeaf8aa71bf0fac1",
+    ),
+    "aarch64": (
+        f"https://github.com/n0-computer/iroh/releases/download/{IROH_VERSION}/iroh-relay-{IROH_VERSION}-aarch64-unknown-linux-musl.tar.gz",
+        "f8ef27631fac213b3ef668d02acd5b3e215292746a3fc71d90c63115446008b1",
+    ),
+}

cmdeploy/src/cmdeploy/postfix/lmtp_header_cleanup

@@ -1,23 +1,3 @@
-# List of headers for incoming messages 
-# that must be retained for functionality and compatibility reasons 
-/^From:/            DUNNO
-/^Message-Id:/      DUNNO
-/^Chat-/            DUNNO
-/^Content-Type:/    DUNNO
-
-# For receiving clear-text messages (still supported in May 2026)
-/^Subject:/         DUNNO
-/^Date:/            DUNNO
-/^To:/              DUNNO
-/^CC:/              DUNNO
-/^References:/      DUNNO
-/^In-Reply-To:/     DUNNO
-
-# Senders might support Autocrypt 1 but not RFC9788 (Header Protection) 
-/^Autocrypt:/       DUNNO
-
-# SecureJoin V2 protocol headers (for backward compatibility) 
-/^Secure-Join/      DUNNO
-
-# Ignore all other headers
-/.*/                IGNORE
+/^DKIM-Signature:/            IGNORE
+/^Authentication-Results:/            IGNORE
+/^Received:/            IGNORE

cmdeploy/src/cmdeploy/postfix/main.cf.j2

@@ -85,6 +85,14 @@ inet_protocols = all
 
 lmtp_header_checks = regexp:/etc/postfix/lmtp_header_cleanup
 
+# Do not apply header checks to MIME headers
+# and other headers that are actually part of the message body.
+# Reference:
+# <https://www.postfix.org/postconf.5.html#disable_mime_input_processing>
+# <https://www.postfix.org/header_checks.5.html>
+# <https://stump.io/blog/2020/11/29/a-little-gotcha-with-postfixs-header_checks/>
+disable_mime_input_processing = yes
+
 mua_client_restrictions = permit_sasl_authenticated, reject
 mua_sender_restrictions = reject_sender_login_mismatch, permit_sasl_authenticated, reject
 mua_helo_restrictions = permit_mynetworks, reject_invalid_helo_hostname, reject_non_fqdn_helo_hostname, permit

cmdeploy/src/cmdeploy/postfix/master.cf.j2

@@ -18,7 +18,7 @@ smtp      inet  n       -       y       -       -       smtpd
   -o smtpd_tls_mandatory_protocols=>=TLSv1.2
   -o smtpd_proxy_filter=127.0.0.1:{{ config.filtermail_smtp_port_incoming }}
   -o smtpd_relay_restrictions=reject_unauth_destination
-submission inet n       -       y       -       5000    smtpd
+submission inet n       -       y       -       {{ config.max_smtp_connections }}    smtpd
   -o syslog_name=postfix/submission
   -o smtpd_tls_security_level=encrypt
   -o smtpd_tls_mandatory_protocols=>=TLSv1.3
@@ -32,9 +32,9 @@ submission inet n       -       y       -       5000    smtpd
   -o smtpd_sender_restrictions=$mua_sender_restrictions
   -o smtpd_recipient_restrictions=
   -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-  -o smtpd_client_connection_count_limit=1000
+  -o smtpd_client_connection_count_limit={{ config.max_smtp_connections // 5 }}
   -o smtpd_proxy_filter=127.0.0.1:{{ config.filtermail_smtp_port }}
-smtps     inet  n       -       y       -       5000    smtpd
+smtps     inet  n       -       y       -       {{ config.max_smtp_connections }}    smtpd
   -o syslog_name=postfix/smtps
   -o smtpd_tls_wrappermode=yes
   -o smtpd_tls_security_level=encrypt
@@ -48,7 +48,7 @@ smtps     inet  n       -       y       -       5000    smtpd
   -o smtpd_sender_restrictions=$mua_sender_restrictions
   -o smtpd_recipient_restrictions=
   -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-  -o smtpd_client_connection_count_limit=1000
+  -o smtpd_client_connection_count_limit={{ config.max_smtp_connections // 5 }}
   -o smtpd_proxy_filter=127.0.0.1:{{ config.filtermail_smtp_port }}
 #628       inet  n       -       y       -       -       qmqpd
 pickup    unix  n       -       y       60      1       pickup
@@ -76,7 +76,6 @@ lmtp      unix  -       -       y       -       -       lmtp
 anvil     unix  -       -       y       -       1       anvil
 scache    unix  -       -       y       -       1       scache
 postlog   unix-dgram n  -       n       -       1       postlogd
-filter    unix -        n       n       -       -       lmtp
 # Local SMTP server for reinjecting outgoing filtered mail.
 127.0.0.1:{{ config.postfix_reinject_port }} inet  n       -       n       -       100      smtpd
   -o syslog_name=postfix/reinject

cmdeploy/src/cmdeploy/service/chatmail-expire.service.f

@@ -5,5 +5,5 @@ After=network.target
 [Service]
 Type=oneshot
 User=vmail
-ExecStart=/usr/local/lib/chatmaild/venv/bin/chatmail-expire /usr/local/lib/chatmaild/chatmail.ini -v --remove
+ExecStart={execpath} {config_path} -v --remove
 

cmdeploy/src/cmdeploy/service/chatmail-fsreport.service.f

@@ -5,5 +5,5 @@ After=network.target
 [Service]
 Type=oneshot
 User=vmail
-ExecStart=/usr/local/lib/chatmaild/venv/bin/chatmail-fsreport /usr/local/lib/chatmaild/chatmail.ini
+ExecStart={execpath} {config_path}
 

cmdeploy/src/cmdeploy/service/doveauth.service.f

@@ -1,12 +1,11 @@
 [Unit]
-Description=Chatmail dict authentication proxy for dovecot
+Description=Chatmail HTTP authentication service for dovecot
 
 [Service]
-ExecStart={execpath} /run/doveauth/doveauth.socket {config_path}
+ExecStart={execpath} {config_path}
 Restart=always
-RestartSec=30
+RestartSec=5
 User=vmail
-RuntimeDirectory=doveauth
 UMask=0077
 
 [Install]

cmdeploy/src/cmdeploy/service/turnserver.service.f

@@ -5,7 +5,7 @@ After=network.target
 [Service]
 Type=simple
 Restart=always
-ExecStart=/usr/local/bin/chatmail-turn --realm {mail_domain} --socket /run/chatmail-turn/turn.socket
+ExecStart={bin_path} --realm {mail_domain} --socket /run/chatmail-turn/turn.socket
 
 # Create /run/chatmail-turn
 RuntimeDirectory=chatmail-turn

cmdeploy/src/cmdeploy/tests/conftest.py

@@ -0,0 +1,27 @@
+"""Run the lua scripts we ship under lupa, which bundles Lua 5.4 like dovecot."""
+
+import pytest
+from chatmaild.tests.plugin import *  # noqa: F403
+from lupa import lua54
+
+from cmdeploy.basedeploy import get_resource
+from cmdeploy.tests.plugin import *  # noqa: F403
+
+
+class Lua:
+    """A Lua runtime to load shipped scripts and mocks into."""
+
+    def __init__(self):
+        self.rt = lua54.LuaRuntime(unpack_returned_tuples=True)
+        self.g = self.rt.globals()
+
+    def load(self, path):
+        self.rt.execute(get_resource(path).read_text())
+
+    def table(self, **kwargs):
+        return self.rt.table(**kwargs)
+
+
+@pytest.fixture
+def lua():
+    return Lua()

cmdeploy/src/cmdeploy/tests/online/test_0_qr.py

@@ -20,17 +20,17 @@ def test_fastcgi_working(maildomain, chatmail_config):
 
 
 @pytest.mark.filterwarnings("ignore::urllib3.exceptions.InsecureRequestWarning")
-def test_newemail_configure(maildomain, rpc, chatmail_config):
+def test_newemail_configure(maildomain, cmrpc, chatmail_config):
     """Test configuring accounts by scanning a QR code works."""
     url = f"DCACCOUNT:https://{maildomain}/new"
     for i in range(3):
-        account_id = rpc.add_account()
+        account_id = cmrpc.add_account()
         if chatmail_config.tls_cert_mode == "self":
             # deltachat core's rustls rejects self-signed HTTPS certs during
             # set_config_from_qr, so fetch credentials via requests instead
             res = requests.post(f"https://{maildomain}/new", verify=False)
             data = res.json()
-            rpc.add_or_update_transport(account_id, {
+            cmrpc.add_or_update_transport(account_id, {
                 "addr": data["email"],
                 "password": data["password"],
                 "imapServer": maildomain,
@@ -38,4 +38,4 @@ def test_newemail_configure(maildomain, rpc, chatmail_config):
                 "certificateChecks": "acceptInvalidCertificates",
             })
         else:
-            rpc.add_transport_from_qr(account_id, url)
+            cmrpc.add_transport_from_qr(account_id, url)

cmdeploy/src/cmdeploy/tests/online/test_2_deltachat.py

@@ -1,10 +1,12 @@
 import ipaddress
+import json
 import re
 import time
 
 import imap_tools
 import pytest
 import requests
+from chatmaild.tests.test_appversions import check_appversions
 
 from cmdeploy.cmdeploy import get_sshexec
 from cmdeploy.remote import rshell
@@ -51,6 +53,17 @@ class TestMetadataTokens:
         assert res == b"1111 2222"
         assert b"Getmetadata completed" in client.readline()
 
+    def test_get_appversions(self, imap_mailbox):
+        "get app version information shipped with the relay"
+        client = imap_mailbox.client
+        client.send(b'a01 GETMETADATA "" /shared/vendor/deltachat/appversions\n')
+        res = client.readline()
+        assert res[:1] == b"*"
+        res = client.readline().strip().rstrip(b")")
+        # the served value is a single line and passes the shipped file's schema
+        check_appversions(json.loads(res))
+        assert b"Getmetadata completed" in client.readline()
+
 
 class TestEndToEndDeltaChat:
     "Tests that use Delta Chat accounts on the chat mail instance."

cmdeploy/src/cmdeploy/tests/plugin.py

@@ -10,24 +10,16 @@ from pathlib import Path
 
 import pytest
 from chatmaild.config import is_valid_ipv4, read_config
-from domain_validator import DomainValidator
 
 
 def format_mail_domain(raw_domain: str) -> str:
     if is_valid_ipv4(raw_domain):
         return f"[{raw_domain}]"
-    DomainValidator().validate_domain_re(raw_domain)
     return raw_domain
 
 
-conftestdir = Path(__file__).parent
-
-
 def pytest_configure(config):
     config._benchresults = {}
-    config.addinivalue_line(
-        "markers", "slow: mark test to require --slow option to run"
-    )
 
 
 def _get_chatmail_config():
@@ -62,8 +54,8 @@ def maildomain(chatmail_config):
 
 
 @pytest.fixture(scope="session")
-def sshdomain(chatmail_config):
-    return os.environ.get("CHATMAIL_SSH", chatmail_config.ssh_host)
+def sshdomain(maildomain):
+    return os.environ.get("CHATMAIL_SSH", maildomain)
 
 
 @pytest.fixture
@@ -213,7 +205,7 @@ class ImapConn:
         status, res = self.conn.select()
         if int(res[0]) == 0:
             raise ValueError("no messages in imap folder")
-        status, results = self.conn.fetch("1:*", "(RFC822)")
+        status, results = self.conn.fetch("1:*", "(BODY.PEEK[])")
         assert status == "OK"
         return results
 
@@ -379,8 +371,12 @@ class ChatmailACFactory:
 
 
 @pytest.fixture(scope="session")
-def rpc(tmp_path_factory):
-    """Start a deltachat-rpc-server process for the test session."""
+def cmrpc(tmp_path_factory):
+    """Start a deltachat-rpc-server process for the test session.
+
+    Not named "rpc": the deltachat-rpc-client pytest plugin registers a
+    function-scoped fixture under that name and would shadow this one.
+    """
 
     # NB: accounts_dir must NOT already exist as directory --
     # core-rust only creates accounts.toml if the dir doesn't exist yet.
@@ -392,10 +388,10 @@ def rpc(tmp_path_factory):
 
 
 @pytest.fixture
-def cmfactory(rpc, gencreds, maildomain, chatmail_config):
+def cmfactory(cmrpc, gencreds, maildomain, chatmail_config):
     """Return a ChatmailACFactory for creating online Delta Chat accounts."""
     return ChatmailACFactory(
-        rpc=rpc,
+        rpc=cmrpc,
         maildomain=maildomain,
         gencreds=gencreds,
         chatmail_config=chatmail_config,

cmdeploy/src/cmdeploy/tests/pytest.ini

@@ -1,2 +0,0 @@
-[pytest]
-addopts = -vrsx --strict-markers

cmdeploy/src/cmdeploy/tests/test_authlua.py

@@ -0,0 +1,216 @@
+"""Test auth.lua script against mocked dovecot auth API."""
+
+import jinja2
+import pytest
+from chatmaild.doveauth import encrypt_password, verify_password
+
+from cmdeploy.basedeploy import get_resource
+
+USER1 = "user12345@chat.example.org"
+USER2 = "newuser12@chat.example.org"
+OK, UNKNOWN, MISMATCH, INTERNAL = 1, -2, -3, -4
+
+DOVECOT_MOCKS = """
+create_status = 200
+
+dovecot = {
+  auth = {
+    PASSDB_RESULT_OK = OK,
+    PASSDB_RESULT_USER_UNKNOWN = UNKNOWN,
+    PASSDB_RESULT_PASSWORD_MISMATCH = MISMATCH,
+    PASSDB_RESULT_INTERNAL_FAILURE = INTERNAL,
+    USERDB_RESULT_OK = OK,
+    USERDB_RESULT_USER_UNKNOWN = UNKNOWN,
+  },
+  http = {
+    client = function(options)
+      client_options = options
+      return {request = function(_, options)
+        create_request = options
+        return {
+          set_payload = function(_, payload) create_payload = payload end,
+          submit = function()
+            return {status = function() return create_status end}
+          end,
+        }
+      end}
+    end,
+  },
+}
+"""
+
+
+def load_authlua(lua, config):
+    lua.g.OK, lua.g.UNKNOWN = OK, UNKNOWN
+    lua.g.MISMATCH, lua.g.INTERNAL = MISMATCH, INTERNAL
+    lua.rt.execute(DOVECOT_MOCKS)
+    template = jinja2.Template(get_resource("dovecot/auth.lua.j2").read_text())
+    lua.rt.execute(template.render(config=config))
+    assert lua.g.script_init() == 0
+    return lua
+
+
+@pytest.fixture
+def authlua(lua, example_config):
+    return load_authlua(lua, example_config)
+
+
+@pytest.fixture
+def request_for(lua):
+    def request_for(addr):
+        def password_verify(_self, hashed, plain):
+            return 1 if verify_password(hashed, plain) else 0
+
+        return lua.table(user=addr, password_verify=password_verify)
+
+    return request_for
+
+
+@pytest.fixture
+def create_user(example_config):
+    def create_user(addr, password):
+        example_config.get_user(addr).set_password(encrypt_password(password))
+
+    return create_user
+
+
+@pytest.fixture
+def write_password_file(example_config):
+    def write_password_file(addr, content):
+        maildir = example_config.mailboxes_dir / addr
+        maildir.mkdir(parents=True, exist_ok=True)
+        maildir.joinpath("password").write_text(content)
+
+    return write_password_file
+
+
+def test_http_client_uses_dovecot_setting_names(authlua):
+    """dovecot's lua http binding silently ignores keys it does not know."""
+    assert dict(authlua.g.client_options) == {
+        "request_timeout_msecs": 5000,
+        "max_attempts": 1,
+    }
+
+
+def test_existing_address_correct_password(authlua, request_for, create_user):
+    create_user(USER1, "correctgoose")
+    res, fields = authlua.g.auth_password_verify(request_for(USER1), "correctgoose")
+    assert res == OK
+    assert fields["uid"] == fields["gid"] == "vmail"
+    assert fields["home"].endswith(USER1)
+    assert authlua.g.create_payload is None
+
+
+def test_existing_address_wrong_password(authlua, request_for, create_user):
+    create_user(USER1, "correctgoose")
+    res, _ = authlua.g.auth_password_verify(request_for(USER1), "wronghorse")
+    assert res == MISMATCH
+
+
+def test_foreign_domain_is_refused_without_calling_out(
+    authlua, request_for, create_user
+):
+    create_user("user12345@evil.example.org", "correctgoose")
+    request = request_for("user12345@evil.example.org")
+    res, _ = authlua.g.auth_password_verify(request, "correctgoose")
+    assert res == UNKNOWN
+    assert authlua.g.auth_userdb_lookup(request)[0] == UNKNOWN
+    assert authlua.g.create_payload is None
+
+
+def test_name_shorter_than_the_domain_is_refused(authlua, request_for):
+    for name in ("x", "", "chat.example.org"):
+        res, _ = authlua.g.auth_password_verify(request_for(name), "correctgoose")
+        assert res == UNKNOWN
+        assert authlua.g.auth_userdb_lookup(request_for(name))[0] == UNKNOWN
+    assert authlua.g.create_payload is None
+
+
+def test_slash_in_username_is_refused(authlua, request_for):
+    request = request_for("../../etc/shadow@chat.example.org")
+    res, _ = authlua.g.auth_password_verify(request, "somepassword")
+    assert res == UNKNOWN
+    assert authlua.g.auth_userdb_lookup(request)[0] == UNKNOWN
+    assert authlua.g.create_payload is None
+
+
+def test_localpart_policy_is_left_to_doveauth(authlua, request_for):
+    authlua.g.create_status = 403
+    res, _ = authlua.g.auth_password_verify(request_for("@chat.example.org"), "somepw")
+    assert res == UNKNOWN
+    assert authlua.g.create_payload == "@chat.example.org\tsomepw"
+
+
+def test_unknown_address_is_created_via_endpoint(authlua, request_for):
+    res, fields = authlua.g.auth_password_verify(request_for(USER2), "brandnewpass")
+    assert res == OK
+    assert fields["home"].endswith(USER2)
+    assert authlua.g.create_payload == f"{USER2}\tbrandnewpass"
+    assert authlua.g.create_request["url"] == "http://127.0.0.1:10084/create"
+
+
+# doveauth refusing is the user's problem, doveauth failing is ours
+@pytest.mark.parametrize("status", [400, 403, 404])
+def test_creation_refused_by_doveauth_is_user_unknown(authlua, request_for, status):
+    authlua.g.create_status = status
+    res, _ = authlua.g.auth_password_verify(request_for(USER2), "brandnewpass")
+    assert res == UNKNOWN
+
+
+# 9003 is dovecot's own CONNECT_FAILED, what a stopped doveauth actually yields
+@pytest.mark.parametrize("status", [500, 502, 9003, 9005])
+def test_creation_that_doveauth_could_not_answer_is_internal_failure(
+    authlua, request_for, status
+):
+    authlua.g.create_status = status
+    res, _ = authlua.g.auth_password_verify(request_for(USER2), "brandnewpass")
+    assert res == INTERNAL
+
+
+def test_userdb_unknown_before_creation_ok_after(authlua, request_for, create_user):
+    request = request_for(USER1)
+    res, _ = authlua.g.auth_userdb_lookup(request)
+    assert res == UNKNOWN
+    # a userdb lookup must never create anything
+    assert authlua.g.create_payload is None
+
+    create_user(USER1, "correctgoose")
+    res, fields = authlua.g.auth_userdb_lookup(request)
+    assert res == OK
+    assert fields["home"].endswith(USER1)
+    assert fields["uid"] == fields["gid"] == "vmail"
+
+
+def test_empty_password_file_is_unknown(authlua, request_for, write_password_file):
+    write_password_file(USER1, "")
+    assert authlua.g.auth_userdb_lookup(request_for(USER1))[0] == UNKNOWN
+
+    write_password_file(USER1, "\n")
+    assert authlua.g.auth_userdb_lookup(request_for(USER1))[0] == UNKNOWN
+
+
+def test_password_file_format_checks(authlua, request_for, write_password_file):
+    write_password_file(USER1, encrypt_password("correctgoose") + "\n")
+    res, _ = authlua.g.auth_password_verify(request_for(USER1), "correctgoose")
+    assert res == OK
+    assert authlua.g.auth_userdb_lookup(request_for(USER1))[0] == OK
+
+    passhash = encrypt_password("correctgoose")
+    write_password_file(USER1, passhash + "\ntrailing junk")
+    authlua.g.create_status = 403
+    res, _ = authlua.g.auth_password_verify(request_for(USER1), "correctgoose")
+    assert res == UNKNOWN
+    assert authlua.g.auth_userdb_lookup(request_for(USER1))[0] == UNKNOWN
+
+
+def test_ipv4_relay_uses_bracketed_domain(lua, ipv4_config, request_for):
+    # mail_domain is "[1.3.3.7]" here, and is_ours must not read it as a pattern
+    authlua = load_authlua(lua, ipv4_config)
+    addr = f"user12345@{ipv4_config.mail_domain}"
+    ipv4_config.get_user(addr).set_password(encrypt_password("correctgoose"))
+
+    res, fields = authlua.g.auth_password_verify(request_for(addr), "correctgoose")
+    assert res == OK
+    assert fields["home"].endswith(addr)
+    assert authlua.g.auth_userdb_lookup(request_for(addr))[0] == OK
+    assert authlua.g.auth_userdb_lookup(request_for(USER1))[0] == UNKNOWN

cmdeploy/src/cmdeploy/tests/test_dovecot_deployer.py

@@ -111,7 +111,7 @@ def test_download_dovecot_package_uses_archive_version_for_url_and_filename(
 
     deb, changed = dovecot_deployer._download_dovecot_package("core", "amd64")
 
-    archive_version = dovecot_deployer.DOVECOT_ARCHIVE_VERSION.replace("+", "%2B")
+    archive_version = dovecot_deployer.DOVECOT_VERSION.replace("+", "%2B")
     expected_deb = f"/root/dovecot-core_{archive_version}_amd64.deb"
 
     # Verify the returned path uses archive version, not package version (with epoch)
@@ -136,6 +136,7 @@ def test_install_skips_dpkg_path_when_epoch_matched_packages_present(
                     "dovecot-core": [dovecot_deployer.DOVECOT_PACKAGE_VERSION],
                     "dovecot-imapd": [dovecot_deployer.DOVECOT_PACKAGE_VERSION],
                     "dovecot-lmtpd": [dovecot_deployer.DOVECOT_PACKAGE_VERSION],
+                    "dovecot-auth-lua": [dovecot_deployer.DOVECOT_PACKAGE_VERSION],
                 },
             ),
             (dovecot_deployer.Arch, "x86_64"),
@@ -180,9 +181,12 @@ def test_install_unsupported_arch_falls_back_to_apt(
     deployer.install()
 
     actual_pkgs = [c["packages"] for c in apt_calls]
-    assert actual_pkgs == [["dovecot-core"], ["dovecot-imapd"], ["dovecot-lmtpd"]], (
-        f"expected apt install of core/imapd/lmtpd, got {actual_pkgs}"
-    )
+    assert actual_pkgs == [
+        ["dovecot-core"],
+        ["dovecot-imapd"],
+        ["dovecot-lmtpd"],
+        ["dovecot-auth-lua"],
+    ], f"expected apt install of core/imapd/lmtpd/auth-lua, got {actual_pkgs}"
     assert track_shell == [], "should not run dpkg for unsupported arch"
     assert deployer.need_restart is True, (
         "need_restart should be True when apt installed a package"

cmdeploy/src/cmdeploy/tests/test_pushlua.py

@@ -0,0 +1,85 @@
+"""Test the push_notification.lua we ship, against a mocked dovecot mail API."""
+
+import textwrap
+
+import pytest
+
+USER1 = "user12345@chat.example.org"
+USER2 = "user67890@chat.example.org"
+
+DOVECOT_MOCKS = textwrap.dedent("""
+    function make_user(username)
+      local function mailbox(_, name)
+        record("mailbox " .. name)
+        return {
+          sync = function() record("sync") end,
+          metadata_set = function(_, k, v)
+            record("metadata_set " .. k .. "=" .. v)
+          end,
+          free = function() record("free") end,
+        }
+      end
+      return {username = username, mailbox = mailbox}
+    end
+""")
+
+
+@pytest.fixture
+def script(lua):
+    lua.rt.execute(DOVECOT_MOCKS)
+    lua.load("dovecot/push_notification.lua")
+    return lua
+
+
+@pytest.fixture
+def deliver(script):
+    def deliver(recipient, sender):
+        calls = []
+        script.g.record = calls.append
+        user = script.g.make_user(recipient)
+        ctx = script.g.dovecot_lua_notify_begin_txn(user)
+        event = script.table(mailbox="INBOX", from_address=sender)
+        script.g.dovecot_lua_notify_event_message_new(ctx, event)
+        script.g.dovecot_lua_notify_end_txn(ctx, True)
+        return calls
+
+    return deliver
+
+
+def test_entry_points_have_the_names_dovecot_calls(script):
+    assert script.g.dovecot_lua_notify_begin_txn is not None
+    assert script.g.dovecot_lua_notify_event_message_new is not None
+    assert script.g.dovecot_lua_notify_end_txn is not None
+
+
+def test_begin_txn_returns_the_user_as_event_context(script):
+    user = script.g.make_user(USER1)
+    ctx = script.g.dovecot_lua_notify_begin_txn(user)
+    ctx.marker = "seen"
+    assert user.marker == "seen"
+
+
+def test_incoming_message_notifies_metadata_server(deliver):
+    assert deliver(USER1, sender=USER2) == [
+        "mailbox INBOX",
+        "sync",
+        "metadata_set /private/messagenew=",
+        "free",
+    ]
+
+
+def test_own_message_does_not_wake_the_sending_device(deliver):
+    assert deliver(USER1, sender=USER1) == [
+        "mailbox INBOX",
+        "sync",
+        "free",
+    ]
+
+
+def test_message_without_from_address_is_notified(deliver):
+    assert deliver(USER1, sender=None) == [
+        "mailbox INBOX",
+        "sync",
+        "metadata_set /private/messagenew=",
+        "free",
+    ]

doc/source/conf.py

@@ -3,6 +3,8 @@
 # For the full list of built-in configuration values, see the documentation:
 # https://www.sphinx-doc.org/en/master/usage/configuration.html
 
+import os
+
 # -- Project information -----------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
@@ -16,12 +18,24 @@ author = 'chatmail collective'
 extensions = [
     #'sphinx.ext.autodoc',
     #'sphinx.ext.viewdoc',
+    'sphinx.ext.extlinks',
     'sphinxcontrib.mermaid',
 ]
 
 templates_path = ['_templates']
 exclude_patterns = []
 
+# Repository links go through the roles below.
+# CI sets DOC_GITHUB_REF to the head commit of a pull request,
+gh_ref = os.environ.get("DOC_GITHUB_REF", "main")
+
+extlinks = {
+    "repofile": (f"https://github.com/chatmail/relay/blob/{gh_ref}/%s", "%s"),
+    "repodir": (f"https://github.com/chatmail/relay/tree/{gh_ref}/%s", "%s"),
+}
+
+# Warn about repository links spelled out in full instead of using the roles.
+extlinks_detect_hardcoded_links = True
 
 
 # -- Options for HTML output -------------------------------------------------

doc/source/faq.rst

@@ -54,7 +54,7 @@ How can I upgrade my chatmail relay?
 ------------------------------------
 
 To upgrade to the latest ``main`` branch,
-``cd`` into your local checkout of `https://github.com/chatmail/relay/`_
+``cd`` into your local checkout of https://github.com/chatmail/relay/
 and run the following commands:
 
    ::

doc/source/getting_started.rst

@@ -14,14 +14,21 @@ Minimal requirements and prerequisites
 
 You will need the following:
 
--  Control over a domain through a DNS provider of your choice.
-   (there is experimental support for :ref:`IP-only relays <iponly>`).
-
--  A Debian 12 server with reachable SMTP/SUBMISSIONS/IMAPS/HTTPS ports.
+-  A Debian 12 **deployment server** with reachable SMTP/SUBMISSIONS/IMAPS/HTTPS ports.
    IPv6 is encouraged if available. Chatmail relay servers only require
    1GB RAM, one CPU, and perhaps 10GB storage for a few thousand active
    chatmail addresses.
 
+-  A Linux or Unix **build machine** with key-based SSH access to the root
+   user of the deployment server.
+   You must add a passphrase-protected private key to your local ssh-agent because you
+   can’t type in your passphrase during deployment.
+   (An ed25519 private key is required due to an `upstream bug in
+   paramiko <https://github.com/paramiko/paramiko/issues/2191>`_)
+
+-  Control over a domain through a DNS provider of your choice
+   (there is experimental support for :ref:`IP-only relays <iponly>`).
+
 
 .. _setup:
 
@@ -31,7 +38,7 @@ Setup with ``scripts/cmdeploy``
 We use ``chat.example.org`` as the chatmail domain in the following
 steps. Please substitute it with your own domain.
 
-1. Setup the initial DNS records for your relay.
+1. Setup the initial DNS records for your deployment server.
    The following is an example in the
    familiar BIND zone file format with a TTL of 1 hour (3600 seconds).
    Please substitute your domain and IP addresses.
@@ -51,25 +58,22 @@ steps. Please substitute it with your own domain.
       The ``mta-sts`` CNAME and ``_mta-sts`` TXT records
       are not needed for such domains.
 
-2. Login to the server with SSH, clone the repository and bootstrap the Python
+2. On your local PC, clone the repository and bootstrap the Python
    virtualenv.
 
    ::
 
-       ssh root@chat.example.org
        git clone https://github.com/chatmail/relay
        cd relay
        scripts/initenv.sh
 
-3. Then, create a chatmail configuration file
+3. On your local build machine (PC), create a chatmail configuration file
    ``chatmail.ini``:
 
    ::
 
        scripts/cmdeploy init chat.example.org  # <-- use your domain
 
-   .. note::
-
    To use self-signed TLS certificates
    instead of Let's Encrypt,
    use a domain name starting with ``_``
@@ -80,7 +84,13 @@ steps. Please substitute it with your own domain.
    See the :doc:`overview`
    for details on certificate provisioning.
 
-4. Now run the deployment script to install the relay to the server:
+4. Verify that SSH root login to the deployment server server works:
+
+   ::
+
+       ssh root@chat.example.org  # <-- use your domain
+
+5. From your local build machine, setup and configure the remote deployment server:
 
    ::
 
@@ -92,6 +102,7 @@ steps. Please substitute it with your own domain.
    public).
 
 
+
 Docker installation
 -------------------
 
@@ -99,32 +110,26 @@ There is experimental support for running chatmail via Docker.
 A monolithic image based on the above cmdeploy method is available `through a separate repository <https://github.com/chatmail/docker/pkgs/container/docker>`_.
 See the `chatmail/docker README <https://github.com/chatmail/docker>`_ for full setup instructions.
 
-
-Next Steps
-----------
-
-Now you should display and check all recommended DNS records
-to enable federation with other relays:
-
-::
-
-   scripts/cmdeploy dns
-
-You should also test whether your chatmail service is working correctly:
-
-::
-
-   scripts/cmdeploy test
-
-Other Helpful Commands
+Other helpful commands
 ----------------------
 
-To check the status of your chatmail relay:
+To check the status of your deployment server running the chatmail service:
 
 ::
 
    scripts/cmdeploy status
 
+To display and check all recommended DNS records:
+
+::
+
+   scripts/cmdeploy dns
+
+To test whether your chatmail service is working correctly:
+
+::
+
+   scripts/cmdeploy test
 
 To measure the performance of your chatmail service:
 
@@ -166,9 +171,8 @@ This starts a local live development cycle for chatmail web pages:
    directory and generating HTML files and copying assets to the
    ``www/build`` directory.
 
--  if you are running scripts/cmdeploy webdev on the relay itself,
-   you need to configure a route in /etc/nginx/nginx.conf
-   to expose the build directory.
+-  Starts a browser window automatically where you can “refresh” as
+   needed.
 
 Custom web pages
 ----------------
@@ -186,7 +190,7 @@ Disable automatic address creation
 --------------------------------------------------------
 
 If you need to stop address creation, e.g. because some script is wildly
-creating addresses, login with ssh to the relay and run:
+creating addresses, login with ssh to the deployment machine and run:
 
 ::
 
@@ -195,6 +199,93 @@ creating addresses, login with ssh to the relay and run:
 Chatmail address creation will be denied while this file is present.
 
 
+.. _system-limits:
+
+Configurable System Limits
+--------------------------
+
+Limits for auto-rejecting address creation
+..........................................
+
+A relay refuses creation of new addresses
+when the machine runs low on resources,
+but existing addresses keep working.
+
+Three ``chatmail.ini`` settings control this,
+shown here with their defaults::
+
+    max_load_1m = 5
+    min_available_memory = 200M
+    min_free_disk_space = 1G
+
+- ``max_load_1m`` is the maximum 1-minute load average,
+  as reported by ``uptime``;
+  it counts processes waiting for disk I/O as well as for CPU.
+  It is deliberately not scaled by the number of CPUs
+  because I/O rather than CPU is what typically limits a relay.
+
+- ``min_available_memory`` is the minimum memory available without swapping.
+
+- ``min_free_disk_space`` is the minimum free disk space
+  on the file system holding the mailboxes.
+
+The defaults suit the small machine described in
+`Minimal requirements and prerequisites`_.
+
+.. note::
+
+   If you run a bigger machine,
+   raise ``max_load_1m`` after watching ``uptime`` under typical load.
+
+Rejections are logged by the ``doveauth`` service,
+so you can check whether a limit is set too tightly::
+
+    journalctl -u doveauth --grep 'registration rejected'
+
+If ``mtail_address`` is set, rejections are also counted
+in the ``rejected_registrations`` metric.
+
+
+Overall IMAP and SMTP connection limits
+.......................................
+
+Two further settings bound how many connections
+the relay accepts at all, again shown with their defaults::
+
+    max_imap_connections = 10000
+    max_smtp_connections = 1000
+
+``max_imap_connections`` becomes the Dovecot imap process limit,
+and ``max_smtp_connections`` the Postfix process limit
+on each of the submission and smtps ports.
+A single client IP may use up to a fifth of ``max_smtp_connections``.
+Each connection costs memory,
+so these limits defend the relay against running out of RAM.
+
+Unless ``imap_compress`` is enabled,
+an IMAP connection that is idle for ``imap_hibernate_timeout``
+is handed over to the ``imap-hibernate`` process
+and does not count towards ``max_imap_connections``,
+which is why a relay can serve far more IMAP clients
+than this setting suggests.
+
+If you run a large relay with 10k or 100k's of addresses,
+check current connection counts before upgrading
+and set the limits accordingly.
+
+To see how close a running relay is to these two limits,
+copy ``scripts/check-connections.sh`` from the relay repository
+onto the relay and run it there::
+
+    imap             5  ports 143,993   (max_imap_connections)
+                     5  dovecot sessions, 0 of them in an active imap process
+    submission       0  ports 465,587   (max_smtp_connections per port)
+    incoming         0  port 25         (from other relays, no chatmail.ini limit)
+
+It counts established sockets with ``ss``
+and cross-checks the IMAP number against ``doveadm who``.
+
+
 Running a relay with self-signed certificates
 ----------------------------------------------
 
@@ -242,3 +333,25 @@ The deploy will verify that both files exist on the server.
    If you use such a setup, you must trigger the reload explicitly after renewal::
 
       systemctl start tls-cert-reload.service
+
+
+Migrating to a new build machine
+----------------------------------
+
+To move or add a build machine,
+clone the relay repository on the new build machine, and copy the ``chatmail.ini`` file from the old build machine.
+Make sure ``rsync`` is installed, then initialize the environment:
+
+::
+
+   ./scripts/initenv.sh
+
+Run safety checks before a new deployment:
+
+::
+
+   ./scripts/cmdeploy dns
+   ./scripts/cmdeploy status
+
+If you keep multiple build machines (ie laptop and desktop), keep ``chatmail.ini`` in sync between
+them.

doc/source/migrate.rst

@@ -1,6 +1,6 @@
 
-Migrating the relay to a new server
-===================================
+Migrating to a new machine
+===========================
 
 This migration tutorial provides a step-wise approach
 to safely migrate a chatmail relay from one remote machine to another.
@@ -96,17 +96,3 @@ in this case, just run ``ssh-keygen -R "mail.example.org"`` as recommended.
    If you have lowered the Time-to-Live for DNS records in step 1,
    better use a higher value again (between 14400 and 86400 seconds) once you are sure everything works.
 
-
-Migrating a local chatmail/relay repository to the server
-=========================================================
-
-To move the directory with your local chatmail/relay repository and ``chatmail.ini`` file,
-clone the `relay repository <https://github.com/chatmail/relay/>` to the server where the relay is running,
-and copy the ``chatmail.ini`` file from your local chatmail/relay repository there.
-
-If you made local changes to the repository,
-you can store them in a file with ``git diff origin/main > local-changes.patch``,
-copy the file to the repository on the server,
-and run ``git apply local-changes.patch``.
-
-Then you can proceed with the `installation steps <setup>`.

doc/source/overview.rst

@@ -6,13 +6,13 @@ Technical overview
 Directories of the relay repository
 -----------------------------------
 
-The `chatmail relay repository <https://github.com/chatmail/relay/tree/main/>`_
+The `chatmail relay repository <https://github.com/chatmail/relay>`_
 has four main directories.
 
 ``scripts/``
 ~~~~~~~~~~~~~
 
-`scripts <https://github.com/chatmail/relay/tree/main/scripts>`_
+:repodir:`scripts`
 offers two convenience tools for beginners:
 
 - ``initenv.sh`` installs a local virtualenv Python environment and
@@ -71,7 +71,7 @@ The deployed system components of a chatmail relay are:
 ``chatmaild/``
 ~~~~~~~~~~~~~~
 
-`chatmaild <https://github.com/chatmail/relay/tree/main/chatmaild>`_
+:repodir:`chatmaild`
 is a Python package containing several small services which handle
 authentication, trigger push notifications on new messages, ensure
 that outbound mails are encrypted, delete inactive users, and some
@@ -83,25 +83,25 @@ that integrate with Dovecot and Postfix to achieve instant-onboarding
 and only relaying OpenPGP end-to-end messages encrypted messages. A
 short overview of ``chatmaild`` services:
 
--  `doveauth <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/doveauth.py>`_
-   implements create-on-login address semantics and is used by Dovecot
-   during IMAP login and by Postfix during SMTP/SUBMISSION login which
-   in turn uses `Dovecot SASL
-   <https://doc.dovecot.org/2.3/configuration_manual/authentication/dict/#complete-example-for-authenticating-via-a-unix-socket>`_
-   to authenticate logins.
+-  :repofile:`doveauth <chatmaild/src/chatmaild/doveauth.py>`
+   implements create-on-login address semantics.
+   Dovecot authenticates IMAP logins, and Postfix SMTP/SUBMISSION logins through `Dovecot SASL
+   <https://doc.dovecot.org/2.3/configuration_manual/authentication/authentication_mechanisms/>`_,
+   from an :repofile:`auth.lua <cmdeploy/src/cmdeploy/dovecot/auth.lua.j2>` script
+   that reads the maildir directly. Only addresses which do not exist yet
+   are passed on to doveauth, which owns the creation policy.
 
--  `chatmail-metadata <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/metadata.py>`_
-   is contacted by a `Dovecot lua
-   script <https://github.com/chatmail/relay/blob/main/cmdeploy/src/cmdeploy/dovecot/push_notification.lua>`_
-   to store user-specific relay-side config. On new messages, it `passes
-   the user’s push notification
-   token <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/notifier.py>`_
+-  :repofile:`chatmail-metadata <chatmaild/src/chatmaild/metadata.py>`
+   is contacted by a
+   :repofile:`Dovecot lua script <cmdeploy/src/cmdeploy/dovecot/push_notification.lua>`
+   to store user-specific relay-side config. On new messages, it
+   :repofile:`passes the user’s push notification token <chatmaild/src/chatmaild/notifier.py>`
    to
    `notifications.delta.chat <https://delta.chat/en/help#instant-delivery>`_
    so the push notifications on the user’s phone can be triggered by
    Apple/Google/Huawei.
 
--  `chatmail-expire <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/expire.py>`_
+-  :repofile:`chatmail-expire <chatmaild/src/chatmaild/expire.py>`
    deletes old messages, large messages, and entire mailboxes
    of users who have not logged in for longer than
    ``delete_inactive_users_after`` days.
@@ -109,15 +109,14 @@ short overview of ``chatmaild`` services:
 -  ``chatmail-quota-expire`` is called by Dovecot's ``quota_warning`` mechanism
    and will automatically remove oldest messages to keep mailboxes well under ``max_mailbox_size``.
 
--  `lastlogin <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/lastlogin.py>`_
+-  :repofile:`lastlogin <chatmaild/src/chatmaild/lastlogin.py>`
    is contacted by Dovecot when a user logs in and stores the date of
    the login.
 
 ``www/``
 ~~~~~~~~~
 
-`www <https://github.com/chatmail/relay/tree/main/www>`_ contains
-the html, css, and markdown files which make up a chatmail relay’s
+:repodir:`www` contains the html, css, and markdown files which make up a chatmail relay’s
 web page. Edit them before deploying to make your chatmail relay
 stand out.
 
@@ -157,7 +156,7 @@ Chatmail relay dependency diagram
         filtermail-outgoing --- |10025 reinject|postfix;
         filtermail-incoming --- |10026 reinject|postfix;
         postfix --- |milter opendkim.sock|OpenDKIM
-        dovecot --- |doveauth.socket|doveauth;
+        dovecot --- |10084 create|doveauth;
         dovecot --- |message delivery|maildir["maildir
         /home/vmail/.../user"];
         dovecot --- |lastlogin.socket|lastlogin;
@@ -225,21 +224,6 @@ Accepting and delivering mail
         nginx -.SMTP inet:465.-> smtpd-smtps
         mta2[Remote relay] -.SMTP inet:25.-> smtpd-smtp
         mta2 -.HTTPS /mxdeliv.-> nginx
-        style postfix fill:#363
-        style qmgr fill:#252
-        style authclean fill:#252
-        style cleanup fill:#252
-        style lmtp-filtermail fill:#252
-        style lmtp fill:#252
-        style bounce fill:#252
-        style smtpd-submission fill:#252
-        style smtpd-smtps fill:#252
-        style smtpd-reinject-outgoing fill:#252
-        style smtpd-reinject-incoming fill:#252
-        style smtpd-smtp fill:#252
-        style filtermail-outgoing fill:#225
-        style filtermail-incoming fill:#225
-        style filtermail-transport fill:#225
 
 Operational details of a chatmail relay
 ----------------------------------------
@@ -264,6 +248,33 @@ Fresh chatmail addresses have a mailbox directory that contains:
    directories will typically be empty unless the user of that address
    hasn’t been online for a while.
 
+App version information (experimental)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A chatmail relay ships the
+:repofile:`appversions.json <chatmaild/src/chatmaild/defaults/appversions.json>`
+file of the ``chatmaild`` package
+and serves its content under the IMAP METADATA key
+``/shared/vendor/deltachat/appversions``.
+Chat apps installed outside of app stores read this key
+to learn about updates and where to download them.
+The mechanism is experimental and may change.
+
+The file travels with the normal deploy:
+update the repository checkout and run ``cmdeploy run``.
+Local modifications of ``appversions.json`` are deployed as-is,
+so you can serve your own app version information,
+including links to app downloads.
+There is no automatic refresh:
+version information changes only when you deploy again.
+
+.. note::
+
+   Note that as of August 2026, only Delta Chat Android Google Play version
+   is beginning to support discovering app versions from relays.
+   Generally, consumers of relay-provided app version information
+   need to verify themselves that downloaded app files are valid.
+
 Active ports
 ~~~~~~~~~~~~
 

doc/source/related.rst

@@ -14,10 +14,11 @@ We know of three work-in-progress alternative implementation efforts:
    it to support all of the features and configuration settings required
    to operate as a chatmail relay.
 
--  `Madmail <https://github.com/themadorg/madmail>`_: an
-   experimental fork of `Maddy Mail Server <https://maddy.email/>`_, modified
-   for chatmail deployments.  It provides a single binary solution
-   for running a chatmail relay.
+-  `Madmail <https://github.com/themadorg/madmail>`_: a Rust-based
+   single-binary chatmail relay.  Madmail v2 is a rewrite of an earlier
+   experimental fork of `Maddy Mail Server <https://maddy.email/>`_.
+   It includes SMTP, IMAP, encryption enforcement, and real-time
+   services (TURN/Iroh), and runs on Linux and Windows.
 
 -  `Chatmail Cookbook <https://github.com/feld/chatmail-cookbook>`_:
    A Chef Cookbook implementing a relay server. The project follows the

scripts/check-connections.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+#
+# Show current IMAP and SMTP connections on a chatmail relay,
+# to compare against the max_imap_connections and max_smtp_connections
+# settings in chatmail.ini.  Run this on the relay itself.
+set -e
+
+# Count established TCP connections whose local port is one of the arguments.
+established() {
+    filter=$(printf 'sport = :%s or ' "$@")
+    ss -Htn state established "( ${filter% or } )" | wc -l
+}
+
+# doveadm prints a header line and then one line per logged-in user,
+# with that user's number of connections in the second column.
+sessions=$(doveadm who | awk 'NR > 1 { n += $2 } END { print n + 0 }')
+
+# Unless imap_compress is enabled, connections idle for
+# imap_hibernate_timeout are handed over to the imap-hibernate
+# process, so they cost no imap process while idle.
+active=$(pgrep -x imap | wc -l)
+
+printf 'imap        %6d  ports 143,993   (max_imap_connections)\n' "$(established 143 993)"
+printf '            %6d  dovecot sessions, %d of them in an active imap process\n' "$sessions" "$active"
+printf 'submission  %6d  ports 465,587   (max_smtp_connections per port)\n' "$(established 465 587)"
+printf 'incoming    %6d  port 25         (from other relays, no chatmail.ini limit)\n' "$(established 25)"

scripts/initenv.sh

@@ -20,6 +20,10 @@ fi
 
 python3 -m venv --upgrade-deps venv
 
+# an editable install puts src/ on sys.path, so a leftover egg-info there is
+# found as a second distribution and keeps removed entry points registered
+rm -rf chatmaild/src/*.egg-info cmdeploy/src/*.egg-info
+
 venv/bin/pip install -e chatmaild 
 venv/bin/pip install -e cmdeploy
 venv/bin/pip install sphinx sphinxcontrib-mermaid sphinx-autobuild furo  # for building the docs