tests: make sure chatmail-metadata was started

fix a flaky test: https://github.com/chatmail/relay/pull/856#issuecomment-3919881473
since #856 chatmail-metadata is restarted every 5 second, if it didn't come up after that, the failure likely sits deeper.

.github/workflows/ci.yaml

@@ -15,7 +15,7 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
       - name: download filtermail
-        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.3.0/filtermail-x86_64 -o /usr/local/bin/filtermail && chmod +x /usr/local/bin/filtermail
+        run: curl -L https://github.com/chatmail/filtermail/releases/download/v0.5.1/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

.gitignore

@@ -4,7 +4,7 @@ __pycache__/
 *$py.class
 *.swp
 *qr-*.png
-chatmail.ini
+chatmail*.ini
 
 
 # C extensions

chatmaild/src/chatmaild/config.py

@@ -60,10 +60,23 @@ class Config:
         self.privacy_pdo = params.get("privacy_pdo")
         self.privacy_supervisor = params.get("privacy_supervisor")
 
-        # TLS certificate management: derived from the domain name.
-        # Domains starting with "_" use self-signed certificates
-        # All other domains use ACME.
-        if self.mail_domain.startswith("_"):
+        # TLS certificate management.
+        # If tls_external_cert_and_key is set, use externally managed certs.
+        # Otherwise derived from the domain name:
+        # - Domains starting with "_" use self-signed certificates
+        # - All other domains use ACME.
+        external = params.get("tls_external_cert_and_key", "").strip()
+
+        if external:
+            parts = external.split()
+            if len(parts) != 2:
+                raise ValueError(
+                    "tls_external_cert_and_key must have two space-separated"
+                    " paths: CERT_PATH KEY_PATH"
+                )
+            self.tls_cert_mode = "external"
+            self.tls_cert_path, self.tls_key_path = parts
+        elif self.mail_domain.startswith("_"):
             self.tls_cert_mode = "self"
             self.tls_cert_path = "/etc/ssl/certs/mailserver.pem"
             self.tls_key_path = "/etc/ssl/private/mailserver.key"

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

@@ -48,6 +48,13 @@ passthrough_senders =
 # (space-separated, item may start with "@" to whitelist whole recipient domains)
 passthrough_recipients =
 
+# 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.
+# Certificate renewal is your responsibility; changed files are
+# picked up automatically by all relay services.
+# tls_external_cert_and_key = /path/to/fullchain.pem /path/to/privkey.pem
+
 # path to www directory - documented here: https://chatmail.at/doc/relay/getting_started.html#custom-web-pages
 #www_folder = www
 

chatmaild/src/chatmaild/tests/test_config.py

@@ -87,3 +87,37 @@ def test_config_tls_self(make_config):
     assert config.tls_cert_mode == "self"
     assert config.tls_cert_path == "/etc/ssl/certs/mailserver.pem"
     assert config.tls_key_path == "/etc/ssl/private/mailserver.key"
+
+
+def test_config_tls_external(make_config):
+    config = make_config(
+        "chat.example.org",
+        {
+            "tls_external_cert_and_key": "/custom/fullchain.pem /custom/privkey.pem",
+        },
+    )
+    assert config.tls_cert_mode == "external"
+    assert config.tls_cert_path == "/custom/fullchain.pem"
+    assert config.tls_key_path == "/custom/privkey.pem"
+
+
+def test_config_tls_external_overrides_underscore(make_config):
+    config = make_config(
+        "_test.example.org",
+        {
+            "tls_external_cert_and_key": "/certs/fullchain.pem /certs/privkey.pem",
+        },
+    )
+    assert config.tls_cert_mode == "external"
+    assert config.tls_cert_path == "/certs/fullchain.pem"
+    assert config.tls_key_path == "/certs/privkey.pem"
+
+
+def test_config_tls_external_bad_format(make_config):
+    with pytest.raises(ValueError, match="two space-separated"):
+        make_config(
+            "chat.example.org",
+            {
+                "tls_external_cert_and_key": "/only/one/path.pem",
+            },
+        )

chatmaild/src/chatmaild/tests/test_filtermail_blackbox.py

@@ -47,6 +47,8 @@ def test_one_mail(
     make_config, make_popen, smtpserver, maildata, filtermail_mode, monkeypatch
 ):
     monkeypatch.setenv("PYTHONUNBUFFERED", "1")
+    # DKIM is tested by cmdeploy tests.
+    monkeypatch.setenv("FILTERMAIL_SKIP_DKIM", "1")
     smtp_inject_port = 20025
     if filtermail_mode == "outgoing":
         settings = dict(
@@ -64,6 +66,10 @@ def test_one_mail(
 
     popen = make_popen(["filtermail", path, filtermail_mode])
     line = popen.stderr.readline().strip()
+
+    # skip a warning that FILTERMAIL_SKIP_DKIM shouldn't be used in prod
+    if b"DKIM verification DISABLED!" in line:
+        line = popen.stderr.readline().strip()
     if b"loop" not in line:
         print(line.decode("ascii"), file=sys.stderr)
         pytest.fail("starting filtermail failed")

cmdeploy/pyproject.toml

@@ -20,6 +20,7 @@ dependencies = [
   "pytest-xdist", 
   "execnet",
   "imap_tools",
+  "deltachat-rpc-client",
 ]
 
 [project.scripts]

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

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

cmdeploy/src/cmdeploy/basedeploy.py

@@ -5,6 +5,11 @@ import os
 from pyinfra.operations import files, server, systemd
 
 
+def has_systemd():
+    """Returns False during Docker image builds or any other non-systemd environment."""
+    return os.path.isdir("/run/systemd/system")
+
+
 def get_resource(arg, pkg=__package__):
     return importlib.resources.files(pkg).joinpath(arg)
 

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -5,7 +5,6 @@ along with command line option and subcommand parsing.
 
 import argparse
 import importlib.resources
-import importlib.util
 import os
 import pathlib
 import shutil
@@ -110,6 +109,9 @@ def run_cmd(args, out):
 
     cmd = f"{pyinf} --ssh-user root {ssh_host} {deploy_path} -y"
     if ssh_host in ["localhost", "@docker"]:
+        if ssh_host == "@docker":
+            env["CHATMAIL_NOPORTCHECK"] = "True"
+            env["CHATMAIL_NOSYSCTL"] = "True"
         cmd = f"{pyinf} @local {deploy_path} -y"
 
     if version.parse(pyinfra.__version__) < version.parse("3"):
@@ -211,14 +213,8 @@ def test_cmd_options(parser):
 
 
 def test_cmd(args, out):
-    """Run local and online tests for chatmail deployment.
+    """Run local and online tests for chatmail deployment."""
 
-    This will automatically pip-install 'deltachat' if it's not available.
-    """
-
-    x = importlib.util.find_spec("deltachat")
-    if x is None:
-        out.check_call(f"{sys.executable} -m pip install deltachat")
     env = os.environ.copy()
     if args.ssh_host:
         env["CHATMAIL_SSH"] = args.ssh_host
@@ -336,7 +332,7 @@ def add_config_option(parser):
         "--config",
         dest="inipath",
         action="store",
-        default=Path("chatmail.ini"),
+        default=Path(os.environ.get("CHATMAIL_INI", "chatmail.ini")),
         type=Path,
         help="path to the chatmail.ini file",
     )

cmdeploy/src/cmdeploy/deployers.py

@@ -2,6 +2,7 @@
 Chat Mail pyinfra deploy.
 """
 
+import os
 import shutil
 import subprocess
 import sys
@@ -10,8 +11,8 @@ from pathlib import Path
 
 from chatmaild.config import read_config
 from pyinfra import facts, host, logger
-from pyinfra.facts import hardware
 from pyinfra.api import FactBase
+from pyinfra.facts import hardware
 from pyinfra.facts.files import Sha256File
 from pyinfra.facts.systemd import SystemdEnabled
 from pyinfra.operations import apt, files, pip, server, systemd
@@ -19,20 +20,22 @@ from pyinfra.operations import apt, files, pip, server, systemd
 from cmdeploy.cmdeploy import Out
 
 from .acmetool import AcmetoolDeployer
-from .selfsigned.deployer import SelfSignedTlsDeployer
 from .basedeploy import (
     Deployer,
     Deployment,
     activate_remote_units,
     configure_remote_units,
     get_resource,
+    has_systemd,
 )
 from .dovecot.deployer import DovecotDeployer
+from .external.deployer import ExternalTlsDeployer
 from .filtermail.deployer import FiltermailDeployer
 from .mtail.deployer import MtailDeployer
 from .nginx.deployer import NginxDeployer
 from .opendkim.deployer import OpendkimDeployer
 from .postfix.deployer import PostfixDeployer
+from .selfsigned.deployer import SelfSignedTlsDeployer
 from .www import build_webpages, find_merge_conflict, get_paths
 
 
@@ -66,6 +69,8 @@ def _build_chatmaild(dist_dir) -> None:
 
 
 def remove_legacy_artifacts():
+    if not has_systemd():
+        return
     # disable legacy doveauth-dictproxy.service
     if host.get_fact(SystemdEnabled).get("doveauth-dictproxy.service"):
         systemd.service(
@@ -300,7 +305,7 @@ class LegacyRemoveDeployer(Deployer):
             present=False,
         )
         # remove echobot if it is still running
-        if host.get_fact(SystemdEnabled).get("echobot.service"):
+        if has_systemd() and host.get_fact(SystemdEnabled).get("echobot.service"):
             systemd.service(
                 name="Disable echobot.service",
                 service="echobot.service",
@@ -536,6 +541,20 @@ class GithashDeployer(Deployer):
         )
 
 
+def get_tls_deployer(config, mail_domain):
+    """Select the appropriate TLS deployer based on config."""
+    tls_domains = [mail_domain, f"mta-sts.{mail_domain}", f"www.{mail_domain}"]
+
+    if config.tls_cert_mode == "acme":
+        return AcmetoolDeployer(config.acme_email, tls_domains)
+    elif config.tls_cert_mode == "self":
+        return SelfSignedTlsDeployer(mail_domain)
+    elif config.tls_cert_mode == "external":
+        return ExternalTlsDeployer(config.tls_cert_path, config.tls_key_path)
+    else:
+        raise ValueError(f"Unknown tls_cert_mode: {config.tls_cert_mode}")
+
+
 def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -> None:
     """Deploy a chat-mail instance.
 
@@ -567,44 +586,44 @@ def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -
             Out().red(f"Deploy failed: mtail_address {config.mtail_address} is not available (VPN up?).\n")
             exit(1)
 
-    port_services = [
-        (["master", "smtpd"], 25),
-        ("unbound", 53),
-    ]
-    if config.tls_cert_mode == "acme":
-        port_services.append(("acmetool", 80))
-    port_services += [
-        (["imap-login", "dovecot"], 143),
-        ("nginx", 443),
-        (["master", "smtpd"], 465),
-        (["master", "smtpd"], 587),
-        (["imap-login", "dovecot"], 993),
-        ("iroh-relay", 3340),
-        ("mtail", 3903),
-        ("stats", 3904),
-        ("nginx", 8443),
-        (["master", "smtpd"], config.postfix_reinject_port),
-        (["master", "smtpd"], config.postfix_reinject_port_incoming),
-        ("filtermail", config.filtermail_smtp_port),
-        ("filtermail", config.filtermail_smtp_port_incoming),
-    ]
-    for service, port in port_services:
-        print(f"Checking if port {port} is available for {service}...")
-        running_service = host.get_fact(Port, port=port)
-        services = [service] if isinstance(service, str) else service
-        if running_service:
-            if running_service not in services:
-                Out().red(
-                    f"Deploy failed: port {port} is occupied by: {running_service}"
-                )
-                exit(1)
+    if not os.environ.get("CHATMAIL_NOPORTCHECK"):
+        port_services = [
+            (["master", "smtpd"], 25),
+            ("unbound", 53),
+        ]
+        if config.tls_cert_mode == "acme":
+            port_services.append(("acmetool", 402))
+        port_services += [
+            (["imap-login", "dovecot"], 143),
+            # acmetool previously listened on port 80,
+            # so don't complain during upgrade that moved it to port 402
+            # and gave the port to nginx.
+            (["acmetool", "nginx"], 80),
+            ("nginx", 443),
+            (["master", "smtpd"], 465),
+            (["master", "smtpd"], 587),
+            (["imap-login", "dovecot"], 993),
+            ("iroh-relay", 3340),
+            ("mtail", 3903),
+            ("stats", 3904),
+            ("nginx", 8443),
+            (["master", "smtpd"], config.postfix_reinject_port),
+            (["master", "smtpd"], config.postfix_reinject_port_incoming),
+            ("filtermail", config.filtermail_smtp_port),
+            ("filtermail", config.filtermail_smtp_port_incoming),
+        ]
+        for service, port in port_services:
+            print(f"Checking if port {port} is available for {service}...")
+            running_service = host.get_fact(Port, port=port)
+            services = [service] if isinstance(service, str) else service
+            if running_service:
+                if running_service not in services:
+                    Out().red(
+                        f"Deploy failed: port {port} is occupied by: {running_service}"
+                    )
+                    exit(1)
 
-    tls_domains = [mail_domain, f"mta-sts.{mail_domain}", f"www.{mail_domain}"]
-
-    if config.tls_cert_mode == "acme":
-        tls_deployer = AcmetoolDeployer(config.acme_email, tls_domains)
-    else:
-        tls_deployer = SelfSignedTlsDeployer(mail_domain)
+    tls_deployer = get_tls_deployer(config, mail_domain)
 
     all_deployers = [
         ChatmailDeployer(mail_domain),

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -1,3 +1,5 @@
+import os
+
 from chatmaild.config import Config
 from pyinfra import host
 from pyinfra.facts.server import Arch, Sysctl
@@ -9,6 +11,7 @@ from cmdeploy.basedeploy import (
     activate_remote_units,
     configure_remote_units,
     get_resource,
+    has_systemd,
 )
 
 
@@ -22,10 +25,11 @@ class DovecotDeployer(Deployer):
 
     def install(self):
         arch = host.get_fact(Arch)
-        if not host.get_fact(SystemdEnabled).get("dovecot.service"):
-            _install_dovecot_package("core", arch)
-            _install_dovecot_package("imapd", arch)
-            _install_dovecot_package("lmtpd", arch)
+        if has_systemd() and "dovecot.service" in host.get_fact(SystemdEnabled):
+            return  # already installed and running
+        _install_dovecot_package("core", arch)
+        _install_dovecot_package("imapd", arch)
+        _install_dovecot_package("lmtpd", arch)
 
     def configure(self):
         configure_remote_units(self.config.mail_domain, self.units)
@@ -116,18 +120,19 @@ def _configure_dovecot(config: Config, debug: bool = False) -> (bool, bool):
 
     # as per https://doc.dovecot.org/2.3/configuration_manual/os/
     # it is recommended to set the following inotify limits
-    for name in ("max_user_instances", "max_user_watches"):
-        key = f"fs.inotify.{name}"
-        if host.get_fact(Sysctl)[key] > 65535:
-            # Skip updating limits if already sufficient
-            # (enables running in incus containers where sysctl readonly)
-            continue
-        server.sysctl(
-            name=f"Change {key}",
-            key=key,
-            value=65535,
-            persist=True,
-        )
+    if not os.environ.get("CHATMAIL_NOSYSCTL"):
+        for name in ("max_user_instances", "max_user_watches"):
+            key = f"fs.inotify.{name}"
+            if host.get_fact(Sysctl)[key] > 65535:
+                # Skip updating limits if already sufficient
+                # (enables running in incus containers where sysctl readonly)
+                continue
+            server.sysctl(
+                name=f"Change {key}",
+                key=key,
+                value=65535,
+                persist=True,
+            )
 
     timezone_env = files.line(
         name="Set TZ environment variable",

cmdeploy/src/cmdeploy/external/deployer.py

@@ -0,0 +1,67 @@
+import io
+
+from pyinfra import host
+from pyinfra.facts.files import File
+from pyinfra.operations import files, systemd
+
+from cmdeploy.basedeploy import Deployer, get_resource
+
+
+class ExternalTlsDeployer(Deployer):
+    """Expects TLS certificates to be managed on the server.
+
+    Validates that the configured certificate and key files
+    exist on the remote host.  Installs a systemd path unit
+    that watches the certificate file and automatically
+    restarts/reloads affected services when it changes.
+    """
+
+    def __init__(self, cert_path, key_path):
+        self.cert_path = cert_path
+        self.key_path = key_path
+
+    def configure(self):
+        # Verify cert and key exist on the remote host using pyinfra facts.
+        for path in (self.cert_path, self.key_path):
+            info = host.get_fact(File, path=path)
+            if info is None:
+                raise Exception(f"External TLS file not found on server: {path}")
+
+        # Deploy the .path unit (templated with the cert path).
+        # pkg=__package__ is required here because the resource files
+        # live in cmdeploy.external, not the default cmdeploy package.
+        source = get_resource("tls-cert-reload.path.f", pkg=__package__)
+        content = source.read_text().format(cert_path=self.cert_path).encode()
+
+        path_unit = files.put(
+            name="Upload tls-cert-reload.path",
+            src=io.BytesIO(content),
+            dest="/etc/systemd/system/tls-cert-reload.path",
+            user="root",
+            group="root",
+            mode="644",
+        )
+
+        service_unit = files.put(
+            name="Upload tls-cert-reload.service",
+            src=get_resource("tls-cert-reload.service", pkg=__package__),
+            dest="/etc/systemd/system/tls-cert-reload.service",
+            user="root",
+            group="root",
+            mode="644",
+        )
+
+        if path_unit.changed or service_unit.changed:
+            self.need_restart = True
+
+    def activate(self):
+        systemd.service(
+            name="Enable tls-cert-reload path watcher",
+            service="tls-cert-reload.path",
+            running=True,
+            enabled=True,
+            restarted=self.need_restart,
+            daemon_reload=self.need_restart,
+        )
+        # No explicit reload needed here: dovecot/nginx read the cert
+        # on startup, and the .path watcher handles live changes.

cmdeploy/src/cmdeploy/external/tls-cert-reload.path.f

@@ -0,0 +1,15 @@
+# Watch the TLS certificate file for changes.
+# When the cert is updated (e.g. renewed by an external process),
+# this triggers tls-cert-reload.service to reload the affected services.
+#
+# NOTE: changes to the certificates are not detected if they cross bind-mount boundaries. 
+# After cert renewal, you must then trigger the reload explicitly:
+#   systemctl start tls-cert-reload.service
+[Unit]
+Description=Watch TLS certificate for changes
+
+[Path]
+PathChanged={cert_path}
+
+[Install]
+WantedBy=multi-user.target

cmdeploy/src/cmdeploy/external/tls-cert-reload.service

@@ -0,0 +1,15 @@
+# Reload services that cache the TLS certificate.
+#
+# dovecot: caches the cert at startup; reload re-reads SSL certs
+#          without dropping existing connections.
+# nginx:   caches the cert at startup; reload gracefully picks up
+#          the new cert for new connections.
+# postfix: reads the cert fresh on each TLS handshake,
+#          does NOT need a reload/restart.
+[Unit]
+Description=Reload TLS services after certificate change
+
+[Service]
+Type=oneshot
+ExecStart=/bin/systemctl try-reload-or-restart dovecot
+ExecStart=/bin/systemctl try-reload-or-restart nginx

cmdeploy/src/cmdeploy/filtermail/deployer.py

@@ -14,10 +14,10 @@ class FiltermailDeployer(Deployer):
 
     def install(self):
         arch = host.get_fact(facts.server.Arch)
-        url = f"https://github.com/chatmail/filtermail/releases/download/v0.3.0/filtermail-{arch}"
+        url = f"https://github.com/chatmail/filtermail/releases/download/v0.5.1/filtermail-{arch}"
         sha256sum = {
-            "x86_64": "f14a31323ae2dad3b59d3fdafcde507521da2f951a9478cd1f2fe2b4463df71d",
-            "aarch64": "933770d75046c4fd7084ce8d43f905f8748333426ad839154f0fc654755ef09f",
+            "x86_64": "adce2ddb461c5fd744df699f3b0b3c33b6d52413c641f18695b93826e5e0d234",
+            "aarch64": "b51cf4248c6c443308f21b1811da1cc919b98b719a2138f4b60940ea093a5422",
         }[arch]
         self.need_restart |= files.download(
             name="Download filtermail",

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

@@ -84,7 +84,7 @@ http {
 		}
 
 		location /new {
-{% if config.tls_cert_mode == "acme" %}
+{% if config.tls_cert_mode != "self" %}
 			if ($request_method = GET) {
 				# Redirect to Delta Chat,
 				# which will in turn do a POST request.
@@ -106,7 +106,7 @@ http {
 		#
 		# Redirects are only for browsers.
 		location /cgi-bin/newemail.py {
-{% if config.tls_cert_mode == "acme" %}
+{% if config.tls_cert_mode != "self" %}
 			if ($request_method = GET) {
 				return 301 dcaccount:https://{{ config.mail_domain }}/new;
 			}
@@ -145,4 +145,25 @@ http {
 		return 301 $scheme://{{ config.mail_domain }}$request_uri;
 		access_log syslog:server=unix:/dev/log,facility=local7;
 	}
+
+	server {
+		listen 80;
+		{% if not disable_ipv6 %}
+		listen [::]:80;
+		{% endif %}
+
+		{% if config.tls_cert_mode == "acme" %}
+		location /.well-known/acme-challenge/ {
+			proxy_pass http://acmetool;
+		}
+		{% endif %}
+
+		return 301 https://$host$request_uri;
+	}
+
+	{% if config.tls_cert_mode == "acme" %}
+	upstream acmetool {
+		server 127.0.0.1:402;
+	}
+	{% endif %}
 }

cmdeploy/src/cmdeploy/opendkim/deployer.py

@@ -37,21 +37,15 @@ class OpendkimDeployer(Deployer):
         )
         need_restart |= main_config.changed
 
-        screen_script = files.put(
-            src=get_resource("opendkim/screen.lua"),
-            dest="/etc/opendkim/screen.lua",
-            user="root",
-            group="root",
-            mode="644",
+        screen_script = files.file(
+            path="/etc/opendkim/screen.lua",
+            present=False,
         )
         need_restart |= screen_script.changed
 
-        final_script = files.put(
-            src=get_resource("opendkim/final.lua"),
-            dest="/etc/opendkim/final.lua",
-            user="root",
-            group="root",
-            mode="644",
+        final_script = files.file(
+            path="/etc/opendkim/final.lua",
+            present=False,
         )
         need_restart |= final_script.changed
 

cmdeploy/src/cmdeploy/opendkim/final.lua

@@ -1,42 +0,0 @@
-mtaname = odkim.get_mtasymbol(ctx, "{daemon_name}")
-if mtaname == "ORIGINATING" then
-	-- Outgoing message will be signed,
-	-- no need to look for signatures.
-	return nil
-end
-
-nsigs = odkim.get_sigcount(ctx)
-if nsigs == nil then
-	return nil
-end
-
-local valid = false
-local error_msg = "No valid DKIM signature found."
-for i = 1, nsigs do
-	sig = odkim.get_sighandle(ctx, i - 1)
-	sigres = odkim.sig_result(sig)
-
-	-- All signatures that do not correspond to From: 
-	-- were ignored in screen.lua and return sigres -1.
-	-- 
-	-- Any valid signature that was not ignored like this
-	-- means the message is acceptable.
-	if sigres == 0 then
-		valid = true
-    else
-        error_msg = "DKIM signature is invalid, error code " .. tostring(sigres) .. ", search https://github.com/trusteddomainproject/OpenDKIM/blob/master/libopendkim/dkim.h#L108"
-	end
-end
-
-if valid then
-	-- Strip all DKIM-Signature headers after successful validation
-	-- Delete in reverse order to avoid index shifting.
-	for i = nsigs, 1, -1 do
-		odkim.del_header(ctx, "DKIM-Signature", i)
-	end
-else
-	odkim.set_reply(ctx, "554", "5.7.1", error_msg)
-	odkim.set_result(ctx, SMFIS_REJECT)
-end
-
-return nil

cmdeploy/src/cmdeploy/opendkim/opendkim.conf

@@ -45,12 +45,6 @@ SignHeaders *,+autocrypt,+content-type
 # Default is empty.
 OversignHeaders from,reply-to,subject,date,to,cc,resent-date,resent-from,resent-sender,resent-to,resent-cc,in-reply-to,references,list-id,list-help,list-unsubscribe,list-subscribe,list-post,list-owner,list-archive,autocrypt
 
-# Script to ignore signatures that do not correspond to the From: domain.
-ScreenPolicyScript /etc/opendkim/screen.lua
-
-# Script to reject mails without a valid DKIM signature.
-FinalPolicyScript /etc/opendkim/final.lua
-
 # In Debian, opendkim runs as user "opendkim". A umask of 007 is required when
 # using a local socket with MTAs that access the socket as a non-privileged
 # user (for example, Postfix). You may need to add user "postfix" to group

cmdeploy/src/cmdeploy/opendkim/screen.lua

@@ -1,21 +0,0 @@
--- Ignore signatures that do not correspond to the From: domain.
-
-from_domain = odkim.get_fromdomain(ctx)
-if from_domain == nil then
-	return nil
-end
-
-n = odkim.get_sigcount(ctx)
-if n == nil then
-	return nil
-end
-
-for i = 1, n do
-	sig = odkim.get_sighandle(ctx, i - 1)
-	sig_domain = odkim.sig_getdomain(sig)
-	if from_domain ~= sig_domain then
-		odkim.sig_ignore(sig)
-	end
-end
-
-return nil

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

@@ -86,7 +86,6 @@ filter    unix -        n       n       -       -       lmtp
 # Local SMTP server for reinjecting incoming filtered mail 
 127.0.0.1:{{ config.postfix_reinject_port_incoming }} inet  n       -       n       -       100      smtpd
   -o syslog_name=postfix/reinject_incoming
-  -o smtpd_milters=unix:opendkim/opendkim.sock
 
 # Cleanup `Received` headers for authenticated mail
 # to avoid leaking client IP.

cmdeploy/src/cmdeploy/selfsigned/deployer.py

@@ -1,8 +1,29 @@
-from pyinfra.operations import apt, files, server
+import shlex
+
+from pyinfra.operations import apt, server
 
 from cmdeploy.basedeploy import Deployer
 
 
+def openssl_selfsigned_args(domain, cert_path, key_path, days=36500):
+    """Return the openssl argument list for a self-signed certificate.
+
+    The certificate uses an EC P-256 key with SAN entries for *domain*,
+    ``www.<domain>`` and ``mta-sts.<domain>``.
+    """
+    return [
+        "openssl", "req", "-x509",
+        "-newkey", "ec", "-pkeyopt", "ec_paramgen_curve:P-256",
+        "-noenc", "-days", str(days),
+        "-keyout", str(key_path),
+        "-out", str(cert_path),
+        "-subj", f"/CN={domain}",
+        "-addext", "extendedKeyUsage=serverAuth,clientAuth",
+        "-addext",
+        f"subjectAltName=DNS:{domain},DNS:www.{domain},DNS:mta-sts.{domain}",
+    ]
+
+
 class SelfSignedTlsDeployer(Deployer):
     """Generates a self-signed TLS certificate for all chatmail endpoints."""
 
@@ -18,18 +39,13 @@ class SelfSignedTlsDeployer(Deployer):
         )
 
     def configure(self):
+        args = openssl_selfsigned_args(
+            self.mail_domain, self.cert_path, self.key_path,
+        )
+        cmd = shlex.join(args)
         server.shell(
             name="Generate self-signed TLS certificate if not present",
-            commands=[
-                f"[ -f {self.cert_path} ] || openssl req -x509"
-                f" -newkey ec -pkeyopt ec_paramgen_curve:P-256"
-                f" -noenc -days 36500"
-                f" -keyout {self.key_path}"
-                f" -out {self.cert_path}"
-                f' -subj "/CN={self.mail_domain}"'
-                f' -addext "extendedKeyUsage=serverAuth,clientAuth"'
-                f' -addext "subjectAltName=DNS:{self.mail_domain},DNS:www.{self.mail_domain},DNS:mta-sts.{self.mail_domain}"',
-            ],
+            commands=[f"[ -f {self.cert_path} ] || {cmd}"],
         )
 
     def activate(self):

cmdeploy/src/cmdeploy/tests/online/benchmark.py

@@ -1,3 +1,4 @@
+import time
 def test_tls_imap(benchmark, imap):
     def imap_connect():
         imap.connect()
@@ -41,9 +42,9 @@ class TestDC:
 
         def dc_ping_pong():
             chat.send_text("ping")
-            msg = ac2._evtracker.wait_next_incoming_message()
-            msg.chat.send_text("pong")
-            ac1._evtracker.wait_next_incoming_message()
+            msg = ac2.wait_for_incoming_msg()
+            msg.get_snapshot().chat.send_text("pong")
+            ac1.wait_for_incoming_msg()
 
         benchmark(dc_ping_pong, 5)
 
@@ -55,6 +56,6 @@ class TestDC:
             for i in range(10):
                 chat.send_text(f"hello {i}")
             for i in range(10):
-                ac2._evtracker.wait_next_incoming_message()
+                ac2.wait_for_incoming_msg()
 
-        benchmark(dc_send_10_receive_10, 5)
+        benchmark(dc_send_10_receive_10, 5, cooldown="auto")

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

@@ -86,10 +86,8 @@ def test_remote(remote, imap_or_smtp):
 
 
 def test_use_two_chatmailservers(cmfactory, maildomain2):
-    ac1 = cmfactory.new_online_configuring_account(cache=False)
-    cmfactory.switch_maildomain(maildomain2)
-    ac2 = cmfactory.new_online_configuring_account(cache=False)
-    cmfactory.bring_accounts_online()
+    ac1 = cmfactory.get_online_account()
+    ac2 = cmfactory.get_online_account(domain=maildomain2)
     cmfactory.get_accepted_chat(ac1, ac2)
     domain1 = ac1.get_config("addr").split("@")[1]
     domain2 = ac2.get_config("addr").split("@")[1]
@@ -149,7 +147,7 @@ def test_reject_missing_dkim(cmsetup, maildata, from_addr):
     conn.starttls()
 
     with conn as s:
-        with pytest.raises(smtplib.SMTPDataError, match="No valid DKIM signature"):
+        with pytest.raises(smtplib.SMTPDataError, match="No DKIM signature found"):
             s.sendmail(from_addr=from_addr, to_addrs=recipient.addr, msg=msg)
 
 

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

@@ -27,6 +27,7 @@ class TestMetadataTokens:
 
     def test_set_get_metadata(self, imap_mailbox):
         "set and get metadata token for an account"
+        time.sleep(5)  # make sure Metadata service had a chance to restart
         client = imap_mailbox.client
         client.send(b'a01 SETMETADATA INBOX (/private/devicetoken "1111" )\n')
         res = client.readline()
@@ -62,8 +63,8 @@ class TestEndToEndDeltaChat:
         chat.send_text("message0")
 
         lp.sec("wait for ac2 to receive message")
-        msg2 = ac2._evtracker.wait_next_incoming_message()
-        assert msg2.text == "message0"
+        msg2 = ac2.wait_for_incoming_msg()
+        assert msg2.get_snapshot().text == "message0"
 
     def test_exceed_quota(
         self, cmfactory, lp, tmpdir, remote, chatmail_config, sshdomain
@@ -98,38 +99,34 @@ class TestEndToEndDeltaChat:
 
         lp.sec("ac2: check quota is triggered")
 
-        starting = True
-        for line in remote.iter_output("journalctl -n0 -f -u dovecot"):
-            if starting:
-                chat.send_text("hello")
-                starting = False
+        def send_hello():
+            chat.send_text("hello")
+
+        for line in remote.iter_output(
+            "journalctl -n1 -f -u dovecot", ready=send_hello
+        ):
             if user not in line:
-                # print(line)
                 continue
             if "quota exceeded" in line:
                 return
 
     def test_securejoin(self, cmfactory, lp, maildomain2):
-        ac1 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.switch_maildomain(maildomain2)
-        ac2 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.bring_accounts_online()
+        ac1 = cmfactory.get_online_account()
+        ac2 = cmfactory.get_online_account(domain=maildomain2)
 
         lp.sec("ac1: create QR code and let ac2 scan it, starting the securejoin")
-        qr = ac1.get_setup_contact_qr()
+        qr = ac1.get_qr_code()
 
         lp.sec("ac2: start QR-code based setup contact protocol")
-        ch = ac2.qr_setup_contact(qr)
+        ch = ac2.secure_join(qr)
         assert ch.id >= 10
-        ac1._evtracker.wait_securejoin_inviter_progress(1000)
+        ac1.wait_for_securejoin_inviter_success()
 
     def test_dkim_header_stripped(self, cmfactory, maildomain2, lp, imap_mailbox):
         """Test that if a DC address receives a message, it has no
         DKIM-Signature and Authentication-Results headers."""
-        ac1 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.switch_maildomain(maildomain2)
-        ac2 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.bring_accounts_online()
+        ac1 = cmfactory.get_online_account()
+        ac2 = cmfactory.get_online_account(domain=maildomain2)
         chat = cmfactory.get_accepted_chat(ac1, imap_mailbox.dc_ac)
         chat.send_text("message0")
         chat2 = cmfactory.get_accepted_chat(ac2, imap_mailbox.dc_ac)
@@ -146,29 +143,28 @@ class TestEndToEndDeltaChat:
                 assert "dkim-signature" not in msg.headers
 
     def test_read_receipts_between_instances(self, cmfactory, lp, maildomain2):
-        ac1 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.switch_maildomain(maildomain2)
-        ac2 = cmfactory.new_online_configuring_account(cache=False)
-        cmfactory.bring_accounts_online()
+        ac1 = cmfactory.get_online_account()
+        ac2 = cmfactory.get_online_account(domain=maildomain2)
 
         lp.sec("setup encrypted comms between ac1 and ac2 on different instances")
-        qr = ac1.get_setup_contact_qr()
-        ch = ac2.qr_setup_contact(qr)
+        qr = ac1.get_qr_code()
+        ch = ac2.secure_join(qr)
         assert ch.id >= 10
-        ac1._evtracker.wait_securejoin_inviter_progress(1000)
+        ac1.wait_for_securejoin_inviter_success()
 
         lp.sec("ac1 sends a message and ac2 marks it as seen")
         chat = ac1.create_chat(ac2)
         msg = chat.send_text("hi")
-        m = ac2._evtracker.wait_next_incoming_message()
+        m = ac2.wait_for_incoming_msg()
         m.mark_seen()
         # we can only indirectly wait for mark-seen to cause an smtp-error
         lp.sec("try to wait for markseen to complete and check error states")
         deadline = time.time() + 3.1
         while time.time() < deadline:
-            msgs = m.chat.get_messages()
+            m_snap = m.get_snapshot()
+            msgs = m_snap.chat.get_messages()
             for msg in msgs:
-                assert "error" not in m.get_message_info()
+                assert "error" not in m.get_info()
             time.sleep(1)
 
 
@@ -180,7 +176,7 @@ def test_hide_senders_ip_address(cmfactory, ssl_context):
     chat = cmfactory.get_accepted_chat(user1, user2)
 
     chat.send_text("testing submission header cleanup")
-    user2._evtracker.wait_next_incoming_message()
+    user2.wait_for_incoming_msg()
     addr = user2.get_config("addr")
     host = addr.split("@")[1]
     pw = user2.get_config("mail_pw")

cmdeploy/src/cmdeploy/tests/plugin.py

@@ -1,5 +1,4 @@
 import imaplib
-import io
 import itertools
 import os
 import random
@@ -35,17 +34,24 @@ def pytest_runtest_setup(item):
             pytest.skip("skipping slow test, use --slow to run")
 
 
-@pytest.fixture(scope="session")
-def chatmail_config(pytestconfig):
-    current = basedir = Path().resolve()
+def _get_chatmail_config():
+    current = Path().resolve()
     while 1:
         path = current.joinpath("chatmail.ini").resolve()
         if path.exists():
-            return read_config(path)
+            return read_config(path), path
         if current == current.parent:
             break
         current = current.parent
+    return None, None
 
+
+@pytest.fixture(scope="session")
+def chatmail_config(pytestconfig):
+    config, path = _get_chatmail_config()
+    if config:
+        return config
+    basedir = Path().resolve()
     pytest.skip(f"no chatmail.ini file found in {basedir} or parent dirs")
 
 
@@ -73,10 +79,17 @@ def sshdomain2(maildomain2):
 
 
 def pytest_report_header():
-    domain = os.environ.get("CHATMAIL_DOMAIN")
-    if domain:
-        text = f"chatmail test instance: {domain}"
-        return ["-" * len(text), text, "-" * len(text)]
+    config, path = _get_chatmail_config()
+    domain2 = os.environ.get("CHATMAIL_DOMAIN2", "NOT SET")
+    domain = config.mail_domain if config else "NOT SET"
+    path = path if path else "NOT SET"
+
+    lines = [
+        f"chatmail.ini {domain} location: {path}",
+        f"chatmail2: {domain2}",
+    ]
+    sep = "-" * max(map(len, lines))
+    return [sep, *lines, sep]
 
 
 @pytest.fixture
@@ -91,15 +104,22 @@ def cm_data(request):
 
 
 @pytest.fixture
-def benchmark(request):
-    def bench(func, num, name=None, reportfunc=None):
+def benchmark(request, chatmail_config):
+    def bench(func, num, name=None, reportfunc=None, cooldown=0.0):
         if name is None:
             name = func.__name__
+        if cooldown == "auto":
+            per_minute = max(chatmail_config.max_user_send_per_minute, 1)
+            cooldown = chatmail_config.max_user_send_burst_size * 60 / per_minute
+
         durations = []
         for i in range(num):
             now = time.time()
             func()
             durations.append(time.time() - now)
+            if cooldown > 0 and i + 1 < num:
+                # Keep post-run cooldown out of measured benchmark duration.
+                time.sleep(cooldown)
         durations.sort()
         request.config._benchresults[name] = (reportfunc, durations)
 
@@ -276,79 +296,95 @@ def gencreds(chatmail_config):
 
 
 #
-# Delta Chat testplugin re-use
+# Delta Chat RPC-based test support
 # use the cmfactory fixture to get chatmail instance accounts
 #
 
+from deltachat_rpc_client import DeltaChat, Rpc
 
-class ChatmailTestProcess:
-    """Provider for chatmail instance accounts as used by deltachat.testplugin.acfactory"""
 
-    def __init__(self, pytestconfig, maildomain, gencreds, chatmail_config):
-        self.pytestconfig = pytestconfig
-        self.maildomain = maildomain
-        assert "." in self.maildomain, maildomain
+class ChatmailACFactory:
+    """RPC-based account factory for chatmail testing."""
+
+    def __init__(self, rpc, maildomain, gencreds, chatmail_config):
+        self.dc = DeltaChat(rpc)
+        self.rpc = rpc
+        self._maildomain = maildomain
         self.gencreds = gencreds
         self.chatmail_config = chatmail_config
-        self._addr2files = {}
 
-    def get_liveconfig_producer(self):
-        while 1:
-            user, password = self.gencreds(self.maildomain)
-            config = {
-                "addr": user,
-                "mail_pw": password,
-            }
-            # speed up account configuration
-            config["mail_server"] = self.maildomain
-            config["send_server"] = self.maildomain
-            if self.chatmail_config.tls_cert_mode == "self":
-                # Accept self-signed TLS certificates
-                config["imap_certificate_checks"] = "3"
-            yield config
+    def _make_transport(self, domain):
+        """Build a transport config dict for the given domain."""
+        addr, password = self.gencreds(domain)
+        transport = {
+            "addr": addr,
+            "password": password,
+            # Setting server explicitly skips requesting autoconfig XML,
+            # see https://datatracker.ietf.org/doc/draft-ietf-mailmaint-autoconfig/
+            "imapServer": domain,
+            "smtpServer": domain,
+        }
+        if self.chatmail_config.tls_cert_mode == "self":
+            transport["certificateChecks"] = "acceptInvalidCertificates"
+        return transport
 
-    def cache_maybe_retrieve_configured_db_files(self, cache_addr, db_target_path):
-        pass
+    def get_online_account(self, domain=None):
+        """Create, configure and bring online a single account."""
+        return self.get_online_accounts(1, domain)[0]
 
-    def cache_maybe_store_configured_db_files(self, acc):
-        pass
+    def get_online_accounts(self, num, domain=None):
+        """Create multiple online accounts in parallel."""
+        domain = domain or self._maildomain
+        futures = []
+        accounts = []
+        for _ in range(num):
+            account = self.dc.add_account()
+            future = account.add_or_update_transport.future(
+                self._make_transport(domain)
+            )
+            futures.append(future)
+
+            # ensure messages stay in INBOX so that they can be
+            # concurrently fetched via extra IMAP connections during tests
+            account.set_config("delete_server_after", "10")
+            accounts.append(account)
+
+        for future in futures:
+            future()
+
+        for account in accounts:
+            account.bring_online()
+        return accounts
+
+    def get_accepted_chat(self, ac1, ac2):
+        """Create a 1:1 chat between ac1 and ac2 accepted on both sides."""
+        ac2.create_chat(ac1)
+        return ac1.create_chat(ac2)
+
+
+@pytest.fixture(scope="session")
+def rpc(tmp_path_factory):
+    """Start a deltachat-rpc-server process for the test session."""
+
+    # NB: accounts_dir must NOT already exist as directory --
+    # core-rust only creates accounts.toml if the dir doesn't exist yet.
+    accounts_dir = str(tmp_path_factory.mktemp("dc") / "accounts")
+    rpc = Rpc(accounts_dir=accounts_dir)
+    rpc.start()
+    yield rpc
+    rpc.close()
 
 
 @pytest.fixture
-def cmfactory(request, gencreds, tmpdir, maildomain, chatmail_config):
-    # cloned from deltachat.testplugin.amfactory
-    pytest.importorskip("deltachat")
-    from deltachat.testplugin import ACFactory
-
-    testproc = ChatmailTestProcess(
-        request.config, maildomain, gencreds, chatmail_config
+def cmfactory(rpc, gencreds, maildomain, chatmail_config):
+    """Return a ChatmailACFactory for creating online Delta Chat accounts."""
+    return ChatmailACFactory(
+        rpc=rpc,
+        maildomain=maildomain,
+        gencreds=gencreds,
+        chatmail_config=chatmail_config,
     )
 
-    class Data:
-        def read_path(self, path):
-            return
-
-    am = ACFactory(request=request, tmpdir=tmpdir, testprocess=testproc, data=Data())
-
-    # Skip upstream's init_imap to prevent extra imap connections not
-    # needed for relay testing
-    am._acsetup.init_imap = lambda acc: None
-
-    # nb. a bit hacky
-    # would probably be better if deltachat's test machinery grows native support
-    def switch_maildomain(maildomain2):
-        am.testprocess.maildomain = maildomain2
-
-    am.switch_maildomain = switch_maildomain
-
-    yield am
-    if hasattr(request.node, "rep_call") and request.node.rep_call.failed:
-        if testproc.pytestconfig.getoption("--extra-info"):
-            logfile = io.StringIO()
-            am.dump_imap_summary(logfile=logfile)
-            print(logfile.getvalue())
-            # request.node.add_report_section("call", "imap-server-state", s)
-
 
 @pytest.fixture
 def remote(sshdomain):
@@ -359,7 +395,7 @@ class Remote:
     def __init__(self, sshdomain):
         self.sshdomain = sshdomain
 
-    def iter_output(self, logcmd=""):
+    def iter_output(self, logcmd="", ready=None):
         getjournal = "journalctl -f" if not logcmd else logcmd
         print(self.sshdomain)
         match self.sshdomain:
@@ -374,10 +410,12 @@ class Remote:
         while 1:
             line = self.popen.stdout.readline()
             res = line.decode().strip().lower()
-            if res:
-                yield res
-            else:
+            if not res:
                 break
+            if ready is not None:
+                ready()
+                ready = None
+            yield res
 
 
 @pytest.fixture

cmdeploy/src/cmdeploy/tests/test_external_tls.py

@@ -0,0 +1,78 @@
+"""Functional tests for tls_external_cert_and_key option."""
+
+import json
+
+import chatmaild.newemail
+import pytest
+from chatmaild.config import read_config, write_initial_config
+
+
+def make_external_config(tmp_path, cert_key=None):
+    inipath = tmp_path / "chatmail.ini"
+    overrides = {}
+    if cert_key is not None:
+        overrides["tls_external_cert_and_key"] = cert_key
+    write_initial_config(inipath, "chat.example.org", overrides=overrides)
+    return inipath
+
+
+def test_external_tls_config_reads_paths(tmp_path):
+    inipath = make_external_config(
+        tmp_path,
+        cert_key=(
+            "/etc/letsencrypt/live/chat.example.org/fullchain.pem"
+            " /etc/letsencrypt/live/chat.example.org/privkey.pem"
+        ),
+    )
+    config = read_config(inipath)
+    assert config.tls_cert_mode == "external"
+    assert (
+        config.tls_cert_path == "/etc/letsencrypt/live/chat.example.org/fullchain.pem"
+    )
+    assert config.tls_key_path == "/etc/letsencrypt/live/chat.example.org/privkey.pem"
+
+
+def test_external_tls_missing_option_uses_acme(tmp_path):
+    config = read_config(make_external_config(tmp_path))
+    assert config.tls_cert_mode == "acme"
+
+
+def test_external_tls_bad_format_raises(tmp_path):
+    inipath = make_external_config(tmp_path, cert_key="/only/one/path.pem")
+    with pytest.raises(ValueError, match="two space-separated"):
+        read_config(inipath)
+
+
+def test_external_tls_three_paths_raises(tmp_path):
+    inipath = make_external_config(tmp_path, cert_key="/a /b /c")
+    with pytest.raises(ValueError, match="two space-separated"):
+        read_config(inipath)
+
+
+def test_external_tls_no_dclogin_url(tmp_path, capsys, monkeypatch):
+    inipath = make_external_config(
+        tmp_path, cert_key="/certs/fullchain.pem /certs/privkey.pem"
+    )
+    monkeypatch.setattr(chatmaild.newemail, "CONFIG_PATH", str(inipath))
+    chatmaild.newemail.print_new_account()
+    out, _ = capsys.readouterr()
+    lines = out.split("\n")
+    dic = json.loads(lines[2])
+    assert "dclogin_url" not in dic
+
+
+def test_external_tls_selects_correct_deployer(tmp_path):
+    from cmdeploy.deployers import get_tls_deployer
+    from cmdeploy.external.deployer import ExternalTlsDeployer
+    from cmdeploy.selfsigned.deployer import SelfSignedTlsDeployer
+
+    inipath = make_external_config(
+        tmp_path, cert_key="/certs/fullchain.pem /certs/privkey.pem"
+    )
+    config = read_config(inipath)
+    deployer = get_tls_deployer(config, "chat.example.org")
+
+    assert isinstance(deployer, ExternalTlsDeployer)
+    assert not isinstance(deployer, SelfSignedTlsDeployer)
+    assert deployer.cert_path == "/certs/fullchain.pem"
+    assert deployer.key_path == "/certs/privkey.pem"

doc/source/getting_started.rst

@@ -198,6 +198,44 @@ and all other relays will accept connections from it
 without requiring certificate verification.
 This is useful for experimental setups and testing.
 
+.. _external-tls:
+
+Running a relay with externally managed certificates
+-----------------------------------------------------
+
+If you already have a TLS certificate manager
+(e.g. Traefik, certbot, or another ACME client)
+running on the deployment server,
+you can configure the relay to use those certificates
+instead of the built-in ``acmetool``.
+
+Set the following in ``chatmail.ini``::
+
+    tls_external_cert_and_key = /path/to/fullchain.pem /path/to/privkey.pem
+
+The paths must point to certificate and key files
+on the deployment server.
+During ``cmdeploy run``, these paths are written into
+the Postfix, Dovecot, and Nginx configurations.
+No certificate files are transferred from the build machine —
+they must already exist on the server,
+managed by your external certificate tool.
+
+The deploy will verify that both files exist on the server.
+``acmetool`` is **not** installed or run in this mode.
+
+.. note::
+
+   You are responsible for certificate renewal.
+   When the certificate file changes on disk,
+   all relay services pick up the new certificate automatically
+   via a systemd path watcher installed during deploy.
+   The watcher uses inotify, which does not cross bind-mount boundaries.
+   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
 ----------------------------------
 

doc/source/overview.rst

@@ -308,6 +308,11 @@ When providing a TLS certificate to your chatmail relay server, make
 sure to provide the full certificate chain and not just the last
 certificate.
 
+If you use an external certificate manager (e.g. Traefik or certbot),
+set ``tls_external_cert_and_key`` in ``chatmail.ini``
+to provide the certificate and key paths.
+See :ref:`external-tls` for details.
+
 If you are running an Exim server and don’t see incoming connections
 from a chatmail relay server in the logs, make sure ``smtp_no_mail`` log
 item is enabled in the config with ``log_selector = +smtp_no_mail``. By