feat: add tool to analyze deferred queue

It prints all destinations with the number of recipients
and all the reasons. Operator can then try
to fix the problems for destinations,
e.g. by manually adding reverse proxy
addresses to /etc/hosts for failing domains
or routing IP addresses to another interface.

.github/workflows/ci.yaml

@@ -9,6 +9,8 @@ on:
   pull_request:
     branches: [ "main" ]
 
+permissions: {}
+
 # Newest push wins: Prevents multiple runs from clashing and wasting runner efforts
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
@@ -25,8 +27,9 @@ jobs:
         # Otherwise `test_deployed_state` will be unhappy.
         with:
           ref: ${{ github.event.pull_request.head.sha }}
+          persist-credentials: false
       - name: download filtermail
-        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.6.1/filtermail-x86_64 -o /usr/local/bin/filtermail && chmod +x /usr/local/bin/filtermail
+        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.6.4/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
@@ -38,6 +41,7 @@ jobs:
       - uses: actions/checkout@v6
         with:
           ref: ${{ github.event.pull_request.head.sha }}
+          persist-credentials: false
 
       - name: initenv 
         run: scripts/initenv.sh

.github/workflows/docker-dispatch.yaml

@@ -0,0 +1,37 @@
+# Notify the docker repo to build and test a new image after relay CI passes.
+#
+# Sends a repository_dispatch event to chatmail/docker with the relay ref
+# and short SHA, which triggers docker-ci.yaml to build, push to GHCR,
+# and run integration tests via cmlxc.
+
+name: Trigger Docker build
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  dispatch:
+    name: Dispatch build to chatmail/docker
+    runs-on: ubuntu-latest
+    if: github.repository == 'chatmail/relay'
+    steps:
+      - name: Compute short SHA
+        id: sha
+        run: echo "short=$(echo '${{ github.sha }}' | cut -c1-7)" >> "$GITHUB_OUTPUT"
+
+      - name: Send repository_dispatch
+        uses: peter-evans/repository-dispatch@ff45666b9427631e3450c54a1bcbee4d9ff4d7c0 # v3
+        with:
+          token: ${{ secrets.CHATMAIL_DOCKER_DISPATCH_TOKEN }}
+          repository: chatmail/docker
+          event-type: relay-updated
+          client-payload: >-
+            {
+              "relay_ref": "${{ github.ref_name }}",
+              "relay_sha": "${{ github.sha }}",
+              "relay_sha_short": "${{ steps.sha.outputs.short }}"
+            }

.github/workflows/docs-preview.yaml

@@ -7,6 +7,8 @@ on:
       - 'scripts/build-docs.sh'
       - '.github/workflows/docs-preview.yaml'
 
+permissions: {}
+
 jobs:
   scripts:
     name: build 
@@ -16,6 +18,8 @@ jobs:
       url: https://staging.chatmail.at/doc/relay/${{ steps.prepare.outputs.prid }}
     steps:
       - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
 
       - name: initenv 
         run: scripts/initenv.sh
@@ -34,18 +38,22 @@ jobs:
       - name: Get Pullrequest ID
         id: prepare
         run: |
-          export PULLREQUEST_ID=$(echo "${{ github.ref }}" | cut -d "/" -f3)
+          export PULLREQUEST_ID=$(echo "${GITHUB_REF}" | cut -d "/" -f3)
           echo "prid=$PULLREQUEST_ID" >> $GITHUB_OUTPUT
           if [ $(expr length "${{ secrets.USERNAME }}") -gt "1" ]; then echo "uploadtoserver=true" >> $GITHUB_OUTPUT; fi
       - run: |
-          echo "baseurl: /${{ steps.prepare.outputs.prid }}" >> _config.yml
+          echo "baseurl: /${STEPS_PREPARE_OUTPUTS_PRID}" >> _config.yml
+        env:
+          STEPS_PREPARE_OUTPUTS_PRID: ${{ steps.prepare.outputs.prid }}
 
       - name: Upload preview
         run: |
           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:/var/www/html/staging.chatmail.at/doc/relay/${STEPS_PREPARE_OUTPUTS_PRID}/"
+        env:
+          STEPS_PREPARE_OUTPUTS_PRID: ${{ steps.prepare.outputs.prid }}
 
       - name: check links 
         working-directory: doc

.github/workflows/docs.yaml

@@ -10,6 +10,8 @@ on:
       - 'scripts/build-docs.sh'
       - '.github/workflows/docs.yaml'
 
+permissions: {}
+
 jobs:
   scripts:
     name: build 
@@ -19,6 +21,8 @@ jobs:
       url: https://chatmail.at/doc/relay/
     steps:
       - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
 
       - name: initenv 
         run: scripts/initenv.sh

.github/workflows/zizmor-scan.yml

@@ -0,0 +1,26 @@
+name: GitHub Actions Security Analysis with zizmor
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["**"]
+
+permissions: {}
+
+jobs:
+  zizmor:
+    name: Run zizmor
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write # Required for upload-sarif (used by zizmor-action) to upload SARIF files.
+      contents: read
+      actions: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+
+      - name: Run zizmor
+        uses: zizmorcore/zizmor-action@b1d7e1fb5de872772f31590499237e7cce841e8e # v0.5.3

.github/zizmor.yml

@@ -0,0 +1,7 @@
+rules:
+  unpinned-uses:
+    config:
+      policies:
+        actions/*: ref-pin
+        dependabot/*: ref-pin
+        chatmail/*: ref-pin

CHANGELOG.md

@@ -1,5 +1,89 @@
 # Changelog for chatmail deployment 
 
+## 1.10.0 2026-04-30
+
+* start mtail after networking is fully up <https://github.com/chatmail/relay/pull/942>
+* support specifying custom filtermail binary through environment variable <https://github.com/chatmail/relay/pull/941>
+* add automated zizmor scanning of github workflows <https://github.com/chatmail/relay/pull/938>
+* added dispatch for *automated builds of chatmail relay docker images* <https://github.com/chatmail/relay/pull/934>
+* do not bind SMTP client sockets to public addresses <https://github.com/chatmail/relay/pull/932>
+* underline in docs that scripts/initenv.sh should be used for building the docs <https://github.com/chatmail/relay/pull/933>
+* automatic oldest-first message removal from mailboxes to always stay under max_mailbox_size <https://github.com/chatmail/relay/pull/929>
+* remove --slow from cmdeploy test <https://github.com/chatmail/relay/pull/931>
+* handle missing inotify sysctl keys in containers <https://github.com/chatmail/relay/pull/930>
+* replace resolvconf with static resolv.conf <https://github.com/chatmail/relay/pull/928>
+* disable fsync for LMTP and IMAP services <https://github.com/chatmail/relay/pull/925>
+* re-use cmlxc workflow, replacing CI with hetzner staging servers with local lxc containers <https://github.com/chatmail/relay/pull/917>
+* explicitly install resolvconf <https://github.com/chatmail/relay/pull/924>
+* detect stale dovecot binary and force restart in activate() <https://github.com/chatmail/relay/pull/922>
+* Rename filtermail_http_port to filtermail_http_port_incoming <https://github.com/chatmail/relay/pull/921>
+* consolidated is_in_container() check https://github.com/chatmail/relay/pull/920>
+* restart dovecot after package replacement (rebase, test condense) <https://github.com/chatmail/relay/pull/913>
+* Set permissions on dovecot pin prefs <https://github.com/chatmail/relay/pull/915>
+* Route `/mxdeliv/` to configurable port <https://github.com/chatmail/relay/pull/901>
+* fix VM detection, automated testing fixes, use newer chatmail-turn and move to standard BIND DNS zone format <https://github.com/chatmail/relay/pull/912>
+* Upgrade to filtermail 0.6.1 <https://github.com/chatmail/relay/pull/910>
+* pin dovecot packages to prevent apt upgrades <https://github.com/chatmail/relay/pull/908>
+* add rpc server to cmdeploy along with client <https://github.com/chatmail/relay/pull/906>
+* remove unused deps from chatmaild <https://github.com/chatmail/relay/pull/905>
+* set default smtp_tls_security_level to "verify" unconditionally <https://github.com/chatmail/relay/pull/902>
+* featprefer IPv4 in SMTP client <https://github.com/chatmail/relay/pull/900>
+* Install dovecot .deb packages atomically <https://github.com/chatmail/relay/pull/899>
+* stop installing cron package <https://github.com/chatmail/relay/pull/898>
+* Rewrite dovecot install logic, update <https://github.com/chatmail/relay/pull/862>
+* fix a test and some linting fixes <https://github.com/chatmail/relay/pull/897>
+* Disable IP verification on domain-literal addresses <https://github.com/chatmail/relay/pull/895>
+* disable installing recommended packages globally on the relay <https://github.com/chatmail/relay/pull/887>
+* multiple bug fixes across chatmaild and cmdeploy <https://github.com/chatmail/relay/pull/883>
+* remove /metrics from the website <https://github.com/chatmail/relay/pull/703>
+* add Prometheus textfile output to fsreport <https://github.com/chatmail/relay/pull/881>
+* chown opendkim: private key <https://github.com/chatmail/relay/pull/879>
+* make sure chatmail-metadata was started <https://github.com/chatmail/relay/pull/882>
+* dovecot update url <https://github.com/chatmail/relay/pull/880>
+* upgrade to filtermail v0.5.2 <https://github.com/chatmail/relay/pull/876>
+* download dovecot packages from github release <https://github.com/chatmail/relay/pull/875>
+* replace DKIM verification with filtermail v0.5 <https://github.com/chatmail/relay/pull/831>
+* remove CFFI deltachat bindings usage, and consolidate test support with rpc-bindings <https://github.com/chatmail/relay/pull/872>
+* prepare chatmaild/cmdeploy changes for Docker support <https://github.com/chatmail/relay/pull/857>
+* stabilize online benchmark timing adding rate-limit-aware cooldown between iterations <https://github.com/chatmail/relay/pull/867>
+* move rate-limit cooldown to benchmark fixture <https://github.com/chatmail/relay/pull/868>
+* reconfigure acmetool from redirector to proxy mode <https://github.com/chatmail/relay/pull/861>
+* make tests work with `--ssh-host localhost` <https://github.com/chatmail/relay/pull/856>
+* mark f-string with f prefix in test_expunged <https://github.com/chatmail/relay/pull/863>
+* install also if dovecot.service=False in SystemdEnabled Fact <https://github.com/chatmail/relay/pull/841>
+* Introduce support for self-signed chatmail relays <https://github.com/chatmail/relay/pull/855>
+* Strip Received headers before delivery <https://github.com/chatmail/relay/pull/849>
+* upgrade to filtermail v0.3 <https://github.com/chatmail/relay/pull/850>
+* fix link to Maddy and update madmail URL <https://github.com/chatmail/relay/pull/847>
+* accept self-signed certificates for IP-only relays <https://github.com/chatmail/relay/pull/846>
+* enforce sending from public IP addresses <https://github.com/chatmail/relay/pull/845>
+* port check: check addresses, fix single services <https://github.com/chatmail/relay/pull/844>
+* remediates issue with improper concat on resolver injection <https://github.com/chatmail/relay/pull/834>
+* ipv6 boolean not being respected during operations <https://github.com/chatmail/relay/pull/832>
+* upgrade to filtermail v0.2 by <https://github.com/chatmail/relay/pull/825>
+* fix link to filtermail <https://github.com/chatmail/relay/pull/824>
+* print timestamps when sending messages <https://github.com/chatmail/relay/pull/823>
+* fix flaky test_exceed_rate_limit <https://github.com/chatmail/relay/pull/822>
+* Replace filtermail with rust reimplementation <https://github.com/chatmail/relay/pull/808>
+* Set default internal SMTP ports in Config <https://github.com/chatmail/relay/pull/819>
+* separate metrics for incoming and outgoing messages <https://github.com/chatmail/relay/pull/820>
+* disable appending the Received header <https://github.com/chatmail/relay/pull/815>
+* fail on errors in postfix/dovecot config <https://github.com/chatmail/relay/pull/813>
+* tweak idle/hibernate metrics some more <https://github.com/chatmail/relay/pull/811>
+* add config flag to export statistics <https://github.com/chatmail/relay/pull/806>
+* add --website-only option to run subcommand <https://github.com/chatmail/relay/pull/768>
+* Strip DKIM-Signature header before LMTP <https://github.com/chatmail/relay/pull/803>
+* properly make sure that postfix gets restarted on failure <https://github.com/chatmail/relay/pull/802>
+* expire.py: use absolute path to maildirsize <https://github.com/chatmail/relay/pull/807>
+* pin Dovecot documentation URLs to version 2.3 <https://github.com/chatmail/relay/pull/800>
+* try to use "build machine" and "deployment server"  consistently  <https://github.com/chatmail/relay/pull/797>
+* adds instructions for migrating control machines <https://github.com/chatmail/relay/pull/795>
+* use consistent naming schema in getting started <https://github.com/chatmail/relay/pull/793>
+* remove jsok/serialize-workflow-action dependency <https://github.com/chatmail/relay/pull/790>
+* streamline migration guide wording, provide titled steps  <https://github.com/chatmail/relay/pull/789>
+* increases default max mailbox size <https://github.com/chatmail/relay/pull/792>
+* use daemon_name for OpenDKIM sign-verify decision instead of IP <https://github.com/chatmail/relay/pull/784>
+
 ## 1.9.0 2025-12-18
 
 ### Documentation

chatmaild/pyproject.toml

@@ -21,8 +21,10 @@ where = ['src']
 [project.scripts]
 doveauth = "chatmaild.doveauth:main"
 chatmail-metadata = "chatmaild.metadata:main"
-chatmail-expire = "chatmaild.expire:main"
+chatmail-expire = "chatmaild.expire:daily_expire_main"
+chatmail-quota-expire = "chatmaild.expire:quota_expire_main"
 chatmail-fsreport = "chatmaild.fsreport:main"
+chatmail-deferred = "chatmaild.deferred:main"
 lastlogin = "chatmaild.lastlogin:main"
 turnserver = "chatmaild.turnserver:main"
 

chatmaild/src/chatmaild/config.py

@@ -1,4 +1,3 @@
-import os
 from pathlib import Path
 
 import iniconfig
@@ -41,14 +40,15 @@ class Config:
         self.filtermail_http_port_incoming = int(
             params.get("filtermail_http_port_incoming", "10082")
         )
+        self.filtermail_lmtp_port_transport = int(
+            params.get("filtermail_lmtp_port_transport", "10083")
+        )
         self.postfix_reinject_port = int(params.get("postfix_reinject_port", "10025"))
         self.postfix_reinject_port_incoming = int(
             params.get("postfix_reinject_port_incoming", "10026")
         )
         self.mtail_address = params.get("mtail_address")
         self.disable_ipv6 = params.get("disable_ipv6", "false").lower() == "true"
-        self.addr_v4 = os.environ.get("CHATMAIL_ADDR_V4", "")
-        self.addr_v6 = os.environ.get("CHATMAIL_ADDR_V6", "")
         self.acme_email = params.get("acme_email", "")
         self.imap_rawlog = params.get("imap_rawlog", "false").lower() == "true"
         self.imap_compress = params.get("imap_compress", "false").lower() == "true"
@@ -95,6 +95,11 @@ class Config:
         # old unused option (except for first migration from sqlite to maildir store)
         self.passdb_path = Path(params.get("passdb_path", "/home/vmail/passdb.sqlite"))
 
+    @property
+    def max_mailbox_size_mb(self):
+        """Return max_mailbox_size as an integer in megabytes."""
+        return parse_size_mb(self.max_mailbox_size)
+
     def _getbytefile(self):
         return open(self._inipath, "rb")
 
@@ -108,6 +113,16 @@ class Config:
         return User(maildir, addr, password_path, uid="vmail", gid="vmail")
 
 
+def parse_size_mb(limit):
+    """Parse a size string like ``500M`` or ``2G`` and return megabytes."""
+    value = limit.strip().upper().removesuffix("B")
+    if value.endswith("G"):
+        return int(value[:-1]) * 1024
+    if value.endswith("M"):
+        return int(value[:-1])
+    return int(value)
+
+
 def write_initial_config(inipath, mail_domain, overrides):
     """Write out default config file, using the specified config value overrides."""
     content = get_default_config_content(mail_domain, **overrides)

chatmaild/src/chatmaild/deferred.py

@@ -0,0 +1,37 @@
+"""
+Analyze deferred mails and print most common failing destinations.
+
+Example:
+
+    python -m chatmaild.deferred
+"""
+
+import json
+import subprocess
+from collections import Counter, defaultdict
+
+
+def main():
+    p = subprocess.Popen(["postqueue", "-j"], text=True, stdout=subprocess.PIPE)
+    domain_reasons = defaultdict(Counter)
+    domain_total = Counter()
+
+    for line in p.stdout:
+        item = json.loads(line)
+        if item["queue_name"] != "deferred":
+            continue
+
+        for recipient in item["recipients"]:
+            _, domain = recipient["address"].rsplit("@", 1)
+            reason = recipient["delay_reason"]
+            domain_total[domain] += 1
+            domain_reasons[domain][reason] += 1
+
+    for domain, total in reversed(domain_total.most_common()):
+        print(f"{domain} ({total} recipients)")
+        for reason, count in domain_reasons[domain].most_common():
+            print(f"  {count}: {reason}")
+
+
+if __name__ == "__main__":
+    main()

chatmaild/src/chatmaild/expire.py

@@ -4,17 +4,26 @@ Expire old messages and addresses.
 """
 
 import os
+import re
 import shutil
 import sys
 import time
 from argparse import ArgumentParser
 from collections import namedtuple
 from datetime import datetime
+from pathlib import Path
 from stat import S_ISREG
 
 from chatmaild.config import read_config
 
 FileEntry = namedtuple("FileEntry", ("path", "mtime", "size"))
+QuotaFileEntry = namedtuple("QuotaFileEntry", ("mtime", "quota_size", "path"))
+
+# Quota cleanup factor of max_mailbox_size. The mailbox is reset to this size.
+QUOTA_CLEANUP_FACTOR = 0.7
+
+# e.g. "cur/1775324677.M448978P3029757.exam,S=3235,W=3305:2,S"
+_dovecot_fn_rex = re.compile(r".+/(\d+)\..+,S=(\d+)")
 
 
 def iter_mailboxes(basedir, maxnum):
@@ -74,6 +83,42 @@ class MailboxStat:
         self.extrafiles.sort(key=lambda x: -x.size)
 
 
+def parse_dovecot_filename(relpath):
+    m = _dovecot_fn_rex.match(relpath)
+    if not m:
+        return None
+    return QuotaFileEntry(int(m.group(1)), int(m.group(2)), relpath)
+
+
+def scan_mailbox_messages(mbox):
+    messages = []
+    for sub in ("cur", "new"):
+        for name in os_listdir_if_exists(mbox / sub):
+            if entry := parse_dovecot_filename(f"{sub}/{name}"):
+                messages.append(entry)
+    return messages
+
+
+def expire_to_target(mbox, target_bytes):
+    messages = scan_mailbox_messages(mbox)
+    total_size = sum(m.quota_size for m in messages)
+    # Keep recent 24 hours of messages protected from expiry because
+    # likely something is wrong with interactions on that address
+    # and quota-full signal can help the address owner's device to notice it
+    undeletable_messages_cutoff = time.time() - (3600 * 24)
+    removed = 0
+    for entry in sorted(messages):
+        if total_size <= target_bytes:
+            break
+        if entry.mtime > undeletable_messages_cutoff:
+            break
+        (mbox / entry.path).unlink(missing_ok=True)
+        total_size -= entry.quota_size
+        removed += 1
+
+    return removed
+
+
 def print_info(msg):
     print(msg, file=sys.stderr)
 
@@ -143,6 +188,19 @@ class Expiry:
             else:
                 continue
             changed = True
+
+        target_bytes = (
+            self.config.max_mailbox_size_mb * 1024 * 1024 * QUOTA_CLEANUP_FACTOR
+        )
+        removed = expire_to_target(Path(mbox.basedir), target_bytes)
+        if removed:
+            changed = True
+            self.del_files += removed
+            if self.verbose:
+                print_info(
+                    f"quota-expire: removed {removed} message(s) from {mboxname}"
+                )
+
         if changed:
             self.remove_file(f"{mbox.basedir}/maildirsize")
 
@@ -154,9 +212,9 @@ class Expiry:
         )
 
 
-def main(args=None):
+def daily_expire_main(args=None):
     """Expire mailboxes and messages according to chatmail config"""
-    parser = ArgumentParser(description=main.__doc__)
+    parser = ArgumentParser(description=daily_expire_main.__doc__)
     ini = "/usr/local/lib/chatmaild/chatmail.ini"
     parser.add_argument(
         "chatmail_ini",
@@ -202,5 +260,33 @@ def main(args=None):
     print(exp.get_summary())
 
 
-if __name__ == "__main__":
-    main(sys.argv[1:])
+def quota_expire_main(args=None):
+    """Remove mailbox messages to stay within a megabyte target.
+
+    This entry point is called by dovecot when a quota threshold is passed.
+    """
+
+    parser = ArgumentParser(description=quota_expire_main.__doc__)
+    parser.add_argument(
+        "target_mb",
+        type=int,
+        help="target mailbox size in megabytes",
+    )
+    parser.add_argument(
+        "mailbox_path",
+        type=Path,
+        help="path to a user mailbox",
+    )
+    args = parser.parse_args(args)
+
+    target_bytes = args.target_mb * 1024 * 1024
+
+    removed_count = expire_to_target(args.mailbox_path, target_bytes)
+    if removed_count:
+        (args.mailbox_path / "maildirsize").unlink(missing_ok=True)
+        print(
+            f"quota-expire: removed {removed_count} message(s)"
+            f" from {args.mailbox_path.name}",
+            file=sys.stderr,
+        )
+    return 0

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

@@ -18,6 +18,7 @@ max_user_send_per_minute = 60
 max_user_send_burst_size = 10
 
 # maximum mailbox size of a chatmail address
+# Oldest messages will be removed automatically, so mailboxes never run full.
 max_mailbox_size = 500M
 
 # maximum message size for an e-mail in bytes

chatmaild/src/chatmaild/tests/test_config.py

@@ -1,6 +1,6 @@
 import pytest
 
-from chatmaild.config import read_config
+from chatmaild.config import parse_size_mb, read_config
 
 
 def test_read_config_basic(example_config):
@@ -121,3 +121,17 @@ def test_config_tls_external_bad_format(make_config):
                 "tls_external_cert_and_key": "/only/one/path.pem",
             },
         )
+
+
+def test_parse_size_mb():
+    assert parse_size_mb("500M") == 500
+    assert parse_size_mb("2G") == 2048
+    assert parse_size_mb("  1g  ") == 1024
+    assert parse_size_mb("100MB") == 100
+    assert parse_size_mb("256") == 256
+
+
+def test_max_mailbox_size_mb(make_config):
+    config = make_config("chat.example.org")
+    assert config.max_mailbox_size == "500M"
+    assert config.max_mailbox_size_mb == 500

chatmaild/src/chatmaild/tests/test_delete_inactive_users.py

@@ -1,7 +1,7 @@
 import time
 
 from chatmaild.doveauth import AuthDictProxy
-from chatmaild.expire import main as main_expire
+from chatmaild.expire import daily_expire_main as main_expire
 
 
 def test_login_timestamps(example_config):

chatmaild/src/chatmaild/tests/test_expire.py

@@ -1,5 +1,7 @@
+import itertools
 import os
 import random
+import time
 from datetime import datetime
 from fnmatch import fnmatch
 from pathlib import Path
@@ -9,13 +11,19 @@ import pytest
 from chatmaild.expire import (
     FileEntry,
     MailboxStat,
+    expire_to_target,
     get_file_entry,
     iter_mailboxes,
     os_listdir_if_exists,
+    parse_dovecot_filename,
+    quota_expire_main,
+    scan_mailbox_messages,
 )
-from chatmaild.expire import main as expiry_main
+from chatmaild.expire import daily_expire_main as expiry_main
 from chatmaild.fsreport import main as report_main
 
+MB = 1024 * 1024
+
 
 def fill_mbox(folderdir):
     password = folderdir.joinpath("password")
@@ -196,3 +204,51 @@ def test_os_listdir_if_exists(tmp_path):
     tmp_path.joinpath("x").write_text("hello")
     assert len(os_listdir_if_exists(str(tmp_path))) == 1
     assert len(os_listdir_if_exists(str(tmp_path.joinpath("123123")))) == 0
+
+
+# --- quota expire tests ---
+
+_msg_counter = itertools.count(1)
+
+
+def _create_message(basedir, sub, size, days_old=0, disk_size=None):
+    seq = next(_msg_counter)
+    mtime = int(time.time() - days_old * 86400)
+    name = f"{mtime}.M1P1Q{seq}.hostname,S={size},W={size}:2,S"
+    path = basedir / sub / name
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_bytes(b"x" * (disk_size if disk_size is not None else size))
+    os.utime(path, (mtime, mtime))
+    return path
+
+
+def test_parse_dovecot_filename():
+    e = parse_dovecot_filename("cur/1775324677.M448978P3029757.exam,S=3235,W=3305:2,S")
+    assert e.path == "cur/1775324677.M448978P3029757.exam,S=3235,W=3305:2,S"
+    assert e.mtime == 1775324677
+    assert e.quota_size == 3235
+    assert parse_dovecot_filename("cur/msg_without_structure") is None
+
+
+def test_expire_to_target(tmp_path):
+    _create_message(tmp_path, "cur", MB, days_old=10, disk_size=100)
+    _create_message(tmp_path, "new", MB, days_old=5)
+    _create_message(tmp_path, "cur", MB, days_old=0)  # undeletable (<1 hour)
+    assert len(scan_mailbox_messages(tmp_path)) == 3
+    # removes oldest first, uses S= size not disk size
+    removed = expire_to_target(tmp_path, MB)
+    assert removed == 2
+    msgs = scan_mailbox_messages(tmp_path)
+    assert len(msgs) == 1
+    # the surviving message is the fresh undeletable one
+    assert msgs[0].mtime > time.time() - 3600
+
+
+def test_quota_expire_main(tmp_path, capsys):
+    mbox = tmp_path / "user@example.org"
+    _create_message(mbox, "cur", 2 * MB, days_old=5)
+    (mbox / "maildirsize").write_text("x")
+    quota_expire_main([str(1), str(mbox)])
+    _, err = capsys.readouterr()
+    assert "quota-expire: removed 1 message(s) from user@example.org" in err
+    assert not (mbox / "maildirsize").exists()

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -101,9 +101,6 @@ def run_cmd(args, out):
     env["CHATMAIL_WEBSITE_ONLY"] = "True" if args.website_only else ""
     env["CHATMAIL_DISABLE_MAIL"] = "True" if args.disable_mail else ""
     env["CHATMAIL_REQUIRE_IROH"] = "True" if require_iroh else ""
-    if not args.dns_check_disabled:
-        env["CHATMAIL_ADDR_V4"] = remote_data.get("A") or ""
-        env["CHATMAIL_ADDR_V6"] = remote_data.get("AAAA") or ""
     deploy_path = importlib.resources.files(__package__).joinpath("run.py").resolve()
     pyinf = "pyinfra --dry" if args.dry_run else "pyinfra"
 
@@ -194,12 +191,6 @@ def status_cmd(args, out):
 
 
 def test_cmd_options(parser):
-    parser.add_argument(
-        "--slow",
-        dest="slow",
-        action="store_true",
-        help="also run slow tests",
-    )
     add_ssh_host_option(parser)
 
 
@@ -221,8 +212,6 @@ def test_cmd(args, out):
         "-v",
         "--durations=5",
     ]
-    if args.slow:
-        pytest_args.append("--slow")
     ret = out.run_ret(pytest_args, env=env)
     return ret
 

cmdeploy/src/cmdeploy/deployers.py

@@ -150,18 +150,40 @@ class UnboundDeployer(Deployer):
         self.need_restart = False
 
     def install(self):
-        # Run local DNS resolver `unbound`. `resolvconf` takes care of
-        # setting up /etc/resolv.conf to use 127.0.0.1 as the resolver.
-
         # 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():
             apt.packages(
                 name="Install unbound",
-                packages=["unbound", "unbound-anchor", "dnsutils", "resolvconf"],
+                packages=["unbound", "unbound-anchor", "dnsutils"],
             )
 
     def configure(self):
+        # Remove dynamic resolver managers that compete for /etc/resolv.conf.
+        apt.packages(
+            name="Purge resolvconf",
+            packages=["resolvconf"],
+            present=False,
+            extra_uninstall_args="--purge",
+        )
+        # systemd-resolved can't be purged due to dependencies; stop and mask.
+        server.shell(
+            name="Stop and mask systemd-resolved",
+            commands=[
+                "systemctl stop systemd-resolved.service || true",
+                "systemctl mask systemd-resolved.service",
+            ],
+        )
+        # Configure unbound resolver with Quad9 fallback and a trailing newline
+        # (SolusVM bug).
+        files.put(
+            name="Write static resolv.conf",
+            src=BytesIO(b"nameserver 127.0.0.1\nnameserver 9.9.9.9\n"),
+            dest="/etc/resolv.conf",
+            user="root",
+            group="root",
+            mode="644",
+        )
         server.shell(
             name="Generate root keys for validating DNSSEC",
             commands=[
@@ -568,14 +590,6 @@ def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -
         Deployment().perform_stages([WebsiteDeployer(config)])
         return
 
-    if host.get_fact(Port, port=53) != "unbound":
-        files.line(
-            name="Add 9.9.9.9 to resolv.conf",
-            path="/etc/resolv.conf",
-            # Guard against resolv.conf missing a trailing newline (SolusVM bug).
-            line="\nnameserver 9.9.9.9",
-        )
-
     # Check if mtail_address interface is available (if configured)
     if config.mtail_address and config.mtail_address not in ('127.0.0.1', '::1', 'localhost'):
         ipv4_addrs = host.get_fact(hardware.Ipv4Addrs)

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -186,7 +186,7 @@ def _configure_dovecot(config: Config, debug: bool = False) -> tuple[bool, bool]
     can_modify = not is_in_container()
     for name in ("max_user_instances", "max_user_watches"):
         key = f"fs.inotify.{name}"
-        value = host.get_fact(Sysctl)[key]
+        value = host.get_fact(Sysctl).get(key, 0)
         if value > 65534:
             continue
         if not can_modify:

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

@@ -149,12 +149,26 @@ plugin {
 }
 
 plugin {
-  # for now we define static quota-rules for all users 
   quota = maildir:User quota
-  quota_rule = *:storage={{ config.max_mailbox_size }}
   quota_max_mail_size={{ config.max_message_size }}
   quota_grace = 0
-  # quota_over_flag_value = TRUE
+
+  quota_rule = *:storage={{ config.max_mailbox_size_mb }}M
+
+  # Trigger at 75%% of quota, expire oldest messages down to 70%%.
+  # The percentages are chosen to prevent current Delta Chat users
+  # from seeing "quota warnings" which trigger at 80% and 95%.
+
+  quota_warning = storage=75%% quota-warning {{ config.max_mailbox_size_mb * 70 // 100 }} {{ config.mailboxes_dir }}/%u
+}
+
+service quota-warning {
+  executable = script /usr/local/lib/chatmaild/venv/bin/chatmail-quota-expire
+  user = vmail
+  unix_listener quota-warning {
+     user = vmail
+     mode = 0600
+  }
 }
 
 # push_notification configuration

cmdeploy/src/cmdeploy/filtermail/deployer.py

@@ -1,3 +1,5 @@
+import os
+
 from pyinfra import facts, host
 from pyinfra.operations import files, systemd
 
@@ -5,7 +7,7 @@ from cmdeploy.basedeploy import Deployer, get_resource
 
 
 class FiltermailDeployer(Deployer):
-    services = ["filtermail", "filtermail-incoming"]
+    services = ["filtermail", "filtermail-incoming", "filtermail-transport"]
     bin_path = "/usr/local/bin/filtermail"
     config_path = "/usr/local/lib/chatmaild/chatmail.ini"
 
@@ -13,11 +15,21 @@ class FiltermailDeployer(Deployer):
         self.need_restart = False
 
     def install(self):
+        local_bin = os.environ.get("CHATMAIL_FILTERMAIL_BINARY")
+        if local_bin:
+            self.need_restart |= files.put(
+                name="Upload locally built filtermail",
+                src=local_bin,
+                dest=self.bin_path,
+                mode="755",
+            ).changed
+            return
+
         arch = host.get_fact(facts.server.Arch)
-        url = f"https://github.com/chatmail/filtermail/releases/download/v0.6.1/filtermail-{arch}"
+        url = f"https://github.com/chatmail/filtermail/releases/download/v0.6.4/filtermail-{arch}"
         sha256sum = {
-            "x86_64": "48b3fb80c092d00b9b0a0ef77a8673496da3b9aed5ec1851e1df936d5589d62f",
-            "aarch64": "c65bd5f45df187d3d65d6965a285583a3be0f44a6916ff12909ff9a8d702c22e",
+            "x86_64": "5295115952c72e4c4ec3c85546e094b4155a4c702c82bd71fcdcb744dc73adf6",
+            "aarch64": "6892244f17b8f26ccb465766e96028e7222b3c8adefca9fc6bfe9ff332ca8dff",
         }[arch]
         self.need_restart |= files.download(
             name="Download filtermail",

cmdeploy/src/cmdeploy/filtermail/filtermail-transport.service.j2

@@ -0,0 +1,11 @@
+[Unit]
+Description=Chatmail transport service
+
+[Service]
+ExecStart={{ bin_path }} {{ config_path }} transport
+Restart=always
+RestartSec=30
+User=vmail
+
+[Install]
+WantedBy=multi-user.target

cmdeploy/src/cmdeploy/mtail/delivered_mail.mtail

@@ -78,3 +78,11 @@ counter rejected_unencrypted_mail_count
 /Rejected unencrypted mail/ {
   rejected_unencrypted_mail_count++
 }
+
+counter quota_expire_runs
+counter quota_expire_removed_files
+
+/quota-expire: removed (?P<count>\d+) message\(s\)/ {
+  quota_expire_runs++
+  quota_expire_removed_files += $count
+}

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

@@ -1,5 +1,6 @@
 [Unit]
 Description=mtail
+After=multi-user.target
 
 [Service]
 Type=simple

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

@@ -73,7 +73,7 @@ http {
 
 		access_log syslog:server=unix:/dev/log,facility=local7;
 
-		location /mxdeliv/ {
+		location /mxdeliv {
 		    proxy_pass http://127.0.0.1:{{ config.filtermail_http_port_incoming }};
 		}
 

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

@@ -69,15 +69,6 @@ mynetworks = 127.0.0.0/8
 {% else %}
 mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
 {% endif %}
-{% if config.addr_v4 %}
-smtp_bind_address = {{ config.addr_v4 }}
-{% endif %}
-{% if config.addr_v6 %}
-smtp_bind_address6 = {{ config.addr_v6 }}
-{% endif %}
-{% if config.addr_v4 or config.addr_v6 %}
-smtp_bind_address_enforce = yes
-{% endif %}
 mailbox_size_limit = 0
 message_size_limit = {{config.max_message_size}}
 recipient_delimiter = +
@@ -88,22 +79,6 @@ inet_protocols = ipv4
 inet_protocols = all
 {% endif %}
 
-# Postfix does not try IPv4 and IPv6 connections
-# concurrently as of version 3.7.11.
-#
-# When relay has both A (IPv4) and AAAA (IPv6) records,
-# but broken IPv6 connectivity,
-# every second message is delayed by the connection timeout
-# <https://www.postfix.org/postconf.5.html#smtp_connect_timeout>
-# which defaults to 30 seconds. Reducing timeouts is not a solution
-# as this will result in a failure to connect to slow servers.
-#
-# As a workaround we always prefer IPv4 when it is available.
-# 
-# The setting is documented at
-# <https://www.postfix.org/postconf.5.html#smtp_address_preference>
-smtp_address_preference=ipv4
-
 virtual_transport = lmtp:unix:private/dovecot-lmtp
 virtual_mailbox_domains = {{ config.mail_domain }}
 lmtp_header_checks = regexp:/etc/postfix/lmtp_header_cleanup
@@ -118,3 +93,10 @@ smtpd_sender_login_maps = regexp:/etc/postfix/login_map
 # Do not lookup SMTP client hostnames to reduce delays
 # and avoid unnecessary DNS requests.
 smtpd_peername_lookup = no
+
+# Use filtermail-transport to relay messages.
+# We can't force postfix to split messages per destination,
+# when specifying a custom next-hop,
+# so instead this is handled in filtermail.
+# We use LMTP instead SMTP so we can communicate per-recipient errors back to postfix.
+default_transport = lmtp-filtermail:inet:[127.0.0.1]:{{ config.filtermail_lmtp_port_transport }}

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

@@ -100,3 +100,8 @@ filter    unix -        n       n       -       -       lmtp
 # cannot send unprotected Subject.
 authclean unix  n       -       -       -       0       cleanup
   -o header_checks=regexp:/etc/postfix/submission_header_cleanup
+
+lmtp-filtermail unix  -       -       y       -       -       lmtp
+  -o syslog_name=postfix/lmtp-filtermail
+  -o lmtp_header_checks=
+  -o lmtp_tls_security_level=none

cmdeploy/src/cmdeploy/tests/online/test_1_basic.py

@@ -221,7 +221,6 @@ def test_rewrite_subject(cmsetup, maildata):
     assert "Subject: Unencrypted subject" not in rcvd_msg
 
 
-@pytest.mark.slow
 def test_exceed_rate_limit(cmsetup, gencreds, maildata, chatmail_config):
     """Test that the per-account send-mail limit is exceeded."""
     user1, user2 = cmsetup.gen_users(2)
@@ -244,7 +243,6 @@ def test_exceed_rate_limit(cmsetup, gencreds, maildata, chatmail_config):
     pytest.fail("Rate limit was not exceeded")
 
 
-@pytest.mark.slow
 def test_expunged(remote, chatmail_config):
     outdated_days = int(chatmail_config.delete_mails_after) + 1
     find_cmds = [

cmdeploy/src/cmdeploy/tests/plugin.py

@@ -23,12 +23,6 @@ def _is_ip(domain):
         return False
 
 
-def pytest_addoption(parser):
-    parser.addoption(
-        "--slow", action="store_true", default=False, help="also run slow tests"
-    )
-
-
 def pytest_configure(config):
     config._benchresults = {}
     config.addinivalue_line(
@@ -36,13 +30,6 @@ def pytest_configure(config):
     )
 
 
-def pytest_runtest_setup(item):
-    markers = list(item.iter_markers(name="slow"))
-    if markers:
-        if not item.config.getoption("--slow"):
-            pytest.skip("skipping slow test, use --slow to run")
-
-
 def _get_chatmail_config():
     inipath = os.environ.get("CHATMAIL_INI")
     if inipath:

cmdeploy/src/cmdeploy/tests/test_helpers.py

@@ -1,11 +1,10 @@
-import importlib.resources
+from pathlib import Path
 
 from cmdeploy.www import build_webpages
 
 
 def test_build_webpages(tmp_path, make_config):
-    pkgroot = importlib.resources.files("cmdeploy")
-    src_dir = pkgroot.joinpath("../../../www/src").resolve()
+    src_dir = (Path(__file__).resolve() / "../../../../../www/src").resolve()
     assert src_dir.exists(), src_dir
     config = make_config("chat.example.org")
     build_dir = tmp_path.joinpath("build")

cmdeploy/src/cmdeploy/www.py

@@ -1,5 +1,4 @@
 import hashlib
-import importlib.resources
 import re
 import time
 import traceback
@@ -37,7 +36,7 @@ def prepare_template(source):
 
 
 def get_paths(config) -> (Path, Path, Path):
-    reporoot = importlib.resources.files(__package__).joinpath("../../../").resolve()
+    reporoot = (Path(__file__).resolve() / "../../../../").resolve()
     www_path = Path(config.www_folder)
     # if www_folder was not set, use default directory
     if config.www_folder == "":
@@ -133,8 +132,7 @@ def find_merge_conflict(src_dir) -> Path:
 
 
 def main():
-    path = importlib.resources.files(__package__)
-    reporoot = path.joinpath("../../../").resolve()
+    reporoot = (Path(__file__).resolve() / "../../../../").resolve()
     inipath = reporoot.joinpath("chatmail.ini")
     config = read_config(inipath)
     config.webdev = True

doc/README.md

@@ -4,12 +4,14 @@
 
 You can use the `make` command and `make html` to build web pages. 
 
-You need a Python environment where the following install was excuted: 
-
-    pip install furo sphinx-autobuild
+You need a Python environment with `sphinx` and other
+dependencies, you can create it by running `scripts/initenv.sh`
+from the repository root.
 
 To develop/change documentation, you can then do: 
 
+    . venv/bin/activate
+    cd doc
     make auto 
 
 A page will open at https://127.0.0.1:8000/ serving the docs and it will 

doc/source/index.rst

@@ -16,5 +16,6 @@ Contributions and feedback welcome through the https://github.com/chatmail/relay
     proxy
     migrate
     overview
+    reverse_dns
     related
     faq

doc/source/overview.rst

@@ -102,8 +102,12 @@ short overview of ``chatmaild`` services:
    Apple/Google/Huawei.
 
 -  `chatmail-expire <https://github.com/chatmail/relay/blob/main/chatmaild/src/chatmaild/expire.py>`_
-   deletes users if they have not logged in for a longer while.
-   The timeframe can be configured in ``chatmail.ini``.
+   deletes old messages, large messages, and entire mailboxes
+   of users who have not logged in for longer than
+   ``delete_inactive_users_after`` days.
+
+-  ``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>`_
    is contacted by Dovecot when a user logs in and stores the date of
@@ -149,6 +153,7 @@ Chatmail relay dependency diagram
         autoconfig.xml --- dovecot;
         postfix --- |10080|filtermail-outgoing;
         postfix --- |10081|filtermail-incoming;
+        postfix --- |10083|filtermail-transport;
         filtermail-outgoing --- |10025 reinject|postfix;
         filtermail-incoming --- |10026 reinject|postfix;
         dovecot --- |doveauth.socket|doveauth;
@@ -156,6 +161,8 @@ Chatmail relay dependency diagram
         /home/vmail/.../user"];
         dovecot --- |lastlogin.socket|lastlogin;
         dovecot --- chatmail-metadata;
+        dovecot --- |quota-warning|chatmail-quota-expire;
+        chatmail-quota-expire --- maildir;
         lastlogin --- maildir;
         doveauth --- maildir;
         chatmail-expire-daily --- maildir;
@@ -289,9 +296,7 @@ ensured by ``filtermail`` proxy.
 TLS requirements
 ~~~~~~~~~~~~~~~~
 
-Postfix is configured to require valid TLS by setting
-`smtp_tls_security_level <https://www.postfix.org/postconf.5.html#smtp_tls_security_level>`_
-to ``verify``.
+Filtermail (used for delivery) requires a valid TLS.
 
 You can test it by resolving ``MX`` records of your relay domain and
 then connecting to MX relays (e.g ``mx.example.org``) with

doc/source/reverse_dns.rst

@@ -0,0 +1,64 @@
+Configuring reverse DNS
+=======================
+
+Some email servers reject the emails
+if they don't pass `FCrDNS`_ check, also known as `iprev`_ check.
+
+.. _FCrDNS: https://en.wikipedia.org/wiki/Forward-confirmed_reverse_DNS
+.. _iprev: https://datatracker.ietf.org/doc/html/rfc8601#section-3
+
+Passing the check requires that the IP address that email is sent from
+should have a ``PTR`` record pointing to the domain name of the server,
+and domain name record should have an ``A/AAAA`` record
+pointing to the IP address.
+
+Modern email relies on DKIM and SPF for authentication,
+while iprev check exists for
+`historical reasons <https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-reverse-mapping-considerations-06#section-2.1>`_.
+Chatmail relays don't resolve ``PTR`` records,
+so you can ignore this section if configuring ``PTR`` records
+is difficult and federation with legacy email servers that don't accept
+valid DKIM signature for authentication is not important.
+
+Multi-homed setups
+------------------
+
+If you have a server with multiple IP addresses,
+also known as multi-homed setup,
+and don't publish all IP addresses in DNS,
+you need to make sure you are using
+the published address when making outgoing connections.
+
+For example, your server may have a static IP
+address, and a so-called Floating IP or Virtual IP
+that can be moved between servers in case of
+migration or for failover.
+By using Floating IP you can avoid downtime
+and keep the IP address reputation
+for destinatinons that rely on IP reputation and IP blocklists.
+In this case you will only publish
+the Floating IP to DNS and only use the static IP
+to SSH into the server.
+
+If you have such setup, make sure that
+you not only set ``PTR`` records for the Floating IP,
+but make outgoing connections using the Floating IP.
+Otherwise reverse DNS check succeed,
+but forward check making sure your domain name points
+to the IP address will fail.
+Such setup is indistinguishable from someone
+setting IP address ``PTR`` with the domain they don't own
+and as a result don't succeed.
+
+On Linux you can configure source IP address with ``ip route`` command,
+for example:
+::
+
+  ip route change default via <default-gateway> dev eth0 src <source-address>
+
+Make sure to persist the change after verifying it is working.
+You can check what your outgoing IP address is
+with ``curl icanhazip.com``.
+Check both the IPv4 and IPv6 addresses.
+For IPv4 address use ``curl ipv4.icanhazip.com`` or ``curl -4 icanhazip.com``
+and similarly for IPv6 if you have it.