feat: add quota-triggered per-user mailbox cleanup

Inflate the Dovecot-visible quota to 140% of the configured
max_mailbox_size so that Delta Chat clients (which warn at
80% of IMAP-reported quota) never show quota warnings.
A quota_warning at 72% of the inflated limit triggers
chatmail-quota-expire, which trims the mailbox to 80% of the
configured limit.  Existing over-quota mailboxes start
receiving mail again immediately after deploy
without any manual operator action needed.

.github/workflows/ci.yaml

@@ -1,15 +1,26 @@
-name: CI
+name: Run unit-tests and container-based deploy+test verification
 
 on:
-  pull_request:
+  # Triggers when a PR is merged into main or a direct push occurs
   push:
+    branches: [ "main" ]
+    
+  # Triggers for any PR (and its subsequent commits) targeting the main branch
+  pull_request:
+    branches: [ "main" ]
+
+# Newest push wins: Prevents multiple runs from clashing and wasting runner efforts
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 
 jobs:
   tox:
     name: isolated chatmaild tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         # Checkout pull request HEAD commit instead of merge commit
         # Otherwise `test_deployed_state` will be unhappy.
         with:
@@ -24,7 +35,9 @@ jobs:
     name: deploy-chatmail tests 
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: initenv 
         run: scripts/initenv.sh
@@ -38,5 +51,23 @@ jobs:
       - name: run deploy-chatmail offline tests 
         run: pytest --pyargs cmdeploy 
 
-      # all other cmdeploy commands require a staging server 
-      # see https://github.com/deltachat/chatmail/issues/100
+  lxc-test:
+    name: LXC deploy and test
+    uses: chatmail/cmlxc/.github/workflows/lxc-test.yml@v0.10.0
+    with:
+      cmlxc_commands: |
+        cmlxc init 
+        # single cmdeploy relay test
+        cmlxc -v deploy-cmdeploy --source ./repo cm0
+        cmlxc -v test-mini cm0
+        cmlxc -v test-cmdeploy cm0
+
+        # cross cmdeploy relay test
+        cmlxc -v deploy-cmdeploy --source ./repo --ipv4-only cm1
+        cmlxc -v test-cmdeploy cm0 cm1
+
+        # cross cmdeploy/madmail relay tests
+        cmlxc -v deploy-madmail mad0
+        cmlxc -v test-cmdeploy cm0 mad0
+        cmlxc -v test-mini cm0 mad0
+        cmlxc -v test-mini mad0 cm0

.github/workflows/test-and-deploy-ipv4only.yaml

@@ -1,104 +0,0 @@
-name: deploy on staging-ipv4.testrun.org, and run tests
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-    paths-ignore:
-      - 'scripts/**'
-      - '**/README.md'
-      - 'CHANGELOG.md'
-      - 'LICENSE'
-
-jobs:
-  deploy:
-    name: deploy on staging-ipv4.testrun.org, and run tests
-    runs-on: ubuntu-latest
-    timeout-minutes: 30
-    environment:
-      name: staging-ipv4.testrun.org
-      url: https://staging-ipv4.testrun.org/
-    concurrency: staging-ipv4.testrun.org
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: prepare SSH
-        run: |
-          mkdir ~/.ssh
-          echo "${{ secrets.STAGING_SSH_KEY }}" >> ~/.ssh/id_ed25519
-          chmod 600 ~/.ssh/id_ed25519
-          ssh-keyscan staging-ipv4.testrun.org > ~/.ssh/known_hosts
-          # save previous acme & dkim state
-          rsync -avz root@staging-ipv4.testrun.org:/var/lib/acme acme-ipv4 || true
-          rsync -avz root@staging-ipv4.testrun.org:/etc/dkimkeys dkimkeys-ipv4 || true
-          # store previous acme & dkim state on ns.testrun.org, if it contains useful certs
-          if [ -f dkimkeys-ipv4/dkimkeys/opendkim.private ]; then rsync -avz -e "ssh -o StrictHostKeyChecking=accept-new" dkimkeys-ipv4 root@ns.testrun.org:/tmp/ || true; fi
-          if [ "$(ls -A acme-ipv4/acme/certs)" ]; then rsync -avz -e "ssh -o StrictHostKeyChecking=accept-new" acme-ipv4 root@ns.testrun.org:/tmp/ || true; fi
-          # make sure CAA record isn't set
-          scp -o StrictHostKeyChecking=accept-new .github/workflows/staging-ipv4.testrun.org-default.zone root@ns.testrun.org:/etc/nsd/staging-ipv4.testrun.org.zone
-          ssh root@ns.testrun.org sed -i '/CAA/d' /etc/nsd/staging-ipv4.testrun.org.zone
-          ssh root@ns.testrun.org nsd-checkzone staging-ipv4.testrun.org /etc/nsd/staging-ipv4.testrun.org.zone
-          ssh root@ns.testrun.org systemctl reload nsd
-
-      - name: rebuild staging-ipv4.testrun.org to have a clean VPS
-        run: |
-            curl -X POST \
-            -H "Authorization: Bearer ${{ secrets.HETZNER_API_TOKEN }}" \
-            -H "Content-Type: application/json" \
-            -d '{"image":"debian-12"}' \
-            "https://api.hetzner.cloud/v1/servers/${{ secrets.STAGING_IPV4_SERVER_ID }}/actions/rebuild"
-
-      - run: scripts/initenv.sh
-
-      - name: append venv/bin to PATH
-        run: echo venv/bin >>$GITHUB_PATH
-
-      - name: upload TLS cert after rebuilding
-        run: |
-          echo " --- wait until staging-ipv4.testrun.org VPS is rebuilt --- "
-          rm ~/.ssh/known_hosts
-          while ! ssh -o ConnectTimeout=180 -o StrictHostKeyChecking=accept-new -v root@staging-ipv4.testrun.org id -u ; do sleep 1 ; done
-          ssh -o StrictHostKeyChecking=accept-new -v root@staging-ipv4.testrun.org id -u
-          # download acme & dkim state from ns.testrun.org
-          rsync -e "ssh -o StrictHostKeyChecking=accept-new" -avz root@ns.testrun.org:/tmp/acme-ipv4/acme acme-restore || true
-          rsync -avz root@ns.testrun.org:/tmp/dkimkeys-ipv4/dkimkeys dkimkeys-restore || true
-          # restore acme & dkim state to staging2.testrun.org
-          rsync -avz acme-restore/acme root@staging-ipv4.testrun.org:/var/lib/ || true
-          rsync -avz dkimkeys-restore/dkimkeys root@staging-ipv4.testrun.org:/etc/ || true
-          ssh -o StrictHostKeyChecking=accept-new -v root@staging-ipv4.testrun.org chown root:root -R /var/lib/acme || true
-
-      - name: run deploy-chatmail offline tests 
-        run: pytest --pyargs cmdeploy 
-
-      - name: setup dependencies
-        run: |
-          ssh root@staging-ipv4.testrun.org apt update
-          ssh root@staging-ipv4.testrun.org apt install -y git python3.11-venv python3-dev gcc
-          ssh root@staging-ipv4.testrun.org git clone https://github.com/chatmail/relay
-          ssh root@staging-ipv4.testrun.org "cd relay && git checkout " ${{ github.head_ref }}
-          ssh root@staging-ipv4.testrun.org "cd relay && scripts/initenv.sh"
-
-      - name: initialize config
-        run: |
-          ssh root@staging-ipv4.testrun.org "cd relay && scripts/cmdeploy init staging-ipv4.testrun.org"
-          ssh root@staging-ipv4.testrun.org "sed -i 's#disable_ipv6 = False#disable_ipv6 = True#' relay/chatmail.ini"
-          ssh root@staging-ipv4.testrun.org "sed -i 's/#\s*mtail_address/mtail_address/' relay/chatmail.ini"
-
-      - run: ssh root@staging-ipv4.testrun.org "cd relay && scripts/cmdeploy run --verbose --skip-dns-check --ssh-host localhost"
-
-      - name: set DNS entries
-        run: |
-          ssh root@staging-ipv4.testrun.org "cd relay && scripts/cmdeploy dns --zonefile staging-generated.zone --ssh-host localhost"
-          ssh root@staging-ipv4.testrun.org cat relay/staging-generated.zone >> .github/workflows/staging-ipv4.testrun.org-default.zone
-          cat .github/workflows/staging-ipv4.testrun.org-default.zone
-          scp .github/workflows/staging-ipv4.testrun.org-default.zone root@ns.testrun.org:/etc/nsd/staging-ipv4.testrun.org.zone
-          ssh root@ns.testrun.org nsd-checkzone staging-ipv4.testrun.org /etc/nsd/staging-ipv4.testrun.org.zone
-          ssh root@ns.testrun.org systemctl reload nsd
-
-      - name: cmdeploy test
-        run: ssh root@staging-ipv4.testrun.org "cd relay && CHATMAIL_DOMAIN2=ci-chatmail.testrun.org scripts/cmdeploy test --slow --ssh-host localhost"
-
-      - name: cmdeploy dns
-        run: ssh root@staging-ipv4.testrun.org "cd relay && scripts/cmdeploy dns -v --ssh-host localhost"
-

.github/workflows/test-and-deploy.yaml

@@ -1,97 +0,0 @@
-name: deploy on staging2.testrun.org, and run tests
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-    paths-ignore:
-      - 'scripts/**'
-      - '**/README.md'
-      - 'CHANGELOG.md'
-      - 'LICENSE'
-
-jobs:
-  deploy:
-    name: deploy on staging2.testrun.org, and run tests
-    runs-on: ubuntu-latest
-    timeout-minutes: 30
-    environment:
-      name: staging2.testrun.org
-      url: https://staging2.testrun.org/
-    concurrency: staging2.testrun.org
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: prepare SSH
-        run: |
-          mkdir ~/.ssh
-          echo "${{ secrets.STAGING_SSH_KEY }}" >> ~/.ssh/id_ed25519
-          chmod 600 ~/.ssh/id_ed25519
-          ssh-keyscan staging2.testrun.org > ~/.ssh/known_hosts
-          # save previous acme & dkim state
-          rsync -avz root@staging2.testrun.org:/var/lib/acme . || true
-          rsync -avz root@staging2.testrun.org:/etc/dkimkeys . || true
-          # store previous acme & dkim state on ns.testrun.org, if it contains useful certs
-          if [ -f dkimkeys/opendkim.private ]; then rsync -avz -e "ssh -o StrictHostKeyChecking=accept-new" dkimkeys root@ns.testrun.org:/tmp/ || true; fi
-          if [ "$(ls -A acme/certs)" ]; then rsync -avz -e "ssh -o StrictHostKeyChecking=accept-new" acme root@ns.testrun.org:/tmp/ || true; fi
-          # make sure CAA record isn't set
-          scp -o StrictHostKeyChecking=accept-new .github/workflows/staging.testrun.org-default.zone root@ns.testrun.org:/etc/nsd/staging2.testrun.org.zone
-          ssh root@ns.testrun.org sed -i '/CAA/d' /etc/nsd/staging2.testrun.org.zone
-          ssh root@ns.testrun.org nsd-checkzone staging2.testrun.org /etc/nsd/staging2.testrun.org.zone
-          ssh root@ns.testrun.org systemctl reload nsd
-
-      - name: rebuild staging2.testrun.org to have a clean VPS
-        run: |
-            curl -X POST \
-            -H "Authorization: Bearer ${{ secrets.HETZNER_API_TOKEN }}" \
-            -H "Content-Type: application/json" \
-            -d '{"image":"debian-12"}' \
-            "https://api.hetzner.cloud/v1/servers/${{ secrets.STAGING_SERVER_ID }}/actions/rebuild"
-
-      - run: scripts/initenv.sh
-
-      - name: append venv/bin to PATH
-        run: echo venv/bin >>$GITHUB_PATH
-
-      - name: upload TLS cert after rebuilding
-        run: |
-          echo " --- wait until staging2.testrun.org VPS is rebuilt --- "
-          rm ~/.ssh/known_hosts
-          while ! ssh -o ConnectTimeout=180 -o StrictHostKeyChecking=accept-new -v root@staging2.testrun.org id -u ; do sleep 1 ; done
-          ssh -o StrictHostKeyChecking=accept-new -v root@staging2.testrun.org id -u
-          # download acme & dkim state from ns.testrun.org
-          rsync -e "ssh -o StrictHostKeyChecking=accept-new" -avz root@ns.testrun.org:/tmp/acme acme-restore || true
-          rsync -avz root@ns.testrun.org:/tmp/dkimkeys dkimkeys-restore || true
-          # restore acme & dkim state to staging2.testrun.org
-          rsync -avz acme-restore/acme root@staging2.testrun.org:/var/lib/ || true
-          rsync -avz dkimkeys-restore/dkimkeys root@staging2.testrun.org:/etc/ || true
-          ssh -o StrictHostKeyChecking=accept-new -v root@staging2.testrun.org chown root:root -R /var/lib/acme || true
-
-      - name: add hpk42 key to staging server
-        run: ssh root@staging2.testrun.org 'curl -s https://github.com/hpk42.keys >> .ssh/authorized_keys'
-
-      - name: run deploy-chatmail offline tests 
-        run: pytest --pyargs cmdeploy 
-
-      - run: |
-          cmdeploy init staging2.testrun.org
-          sed -i 's/#\s*mtail_address/mtail_address/' chatmail.ini
-
-      - run: cmdeploy run --verbose --skip-dns-check
-
-      - name: set DNS entries
-        run: |
-          cmdeploy dns --zonefile staging-generated.zone --verbose
-          cat staging-generated.zone >> .github/workflows/staging.testrun.org-default.zone
-          cat .github/workflows/staging.testrun.org-default.zone
-          scp .github/workflows/staging.testrun.org-default.zone root@ns.testrun.org:/etc/nsd/staging2.testrun.org.zone
-          ssh root@ns.testrun.org nsd-checkzone staging2.testrun.org /etc/nsd/staging2.testrun.org.zone
-          ssh root@ns.testrun.org systemctl reload nsd
-
-      - name: cmdeploy test
-        run: CHATMAIL_DOMAIN2=ci-chatmail.testrun.org cmdeploy test --slow
-
-      - name: cmdeploy dns
-        run: cmdeploy dns -v
-

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Changelog for chatmail deployment 
 
+## Unreleased
+
+### Features
+
+- Add per-user quota-triggered cleanup (`chatmail-quota-expire`).
+  When a mailbox exceeds the configured ``max_mailbox_size``,
+  Dovecot runs the new script which removes the oldest
+  messages until usage drops to a safe level.
+  No operator action is required after upgrading;
+  existing over-quota mailboxes start receiving mail
+  again immediately and are cleaned up automatically.
+  The daily `chatmail-expire` timer continues to handle
+  deletion of old messages, large messages,
+  and inactive user mailboxes.
+
 ## 1.9.0 2025-12-18
 
 ### Documentation

chatmaild/pyproject.toml

@@ -22,6 +22,7 @@ where = ['src']
 doveauth = "chatmaild.doveauth:main"
 chatmail-metadata = "chatmaild.metadata:main"
 chatmail-expire = "chatmaild.expire:main"
+chatmail-quota-expire = "chatmaild.quota_expire:main"
 chatmail-fsreport = "chatmaild.fsreport:main"
 lastlogin = "chatmaild.lastlogin:main"
 turnserver = "chatmaild.turnserver:main"

chatmaild/src/chatmaild/config.py

@@ -38,7 +38,9 @@ class Config:
         self.filtermail_smtp_port_incoming = int(
             params.get("filtermail_smtp_port_incoming", "10081")
         )
-        self.filtermail_http_port = int(params.get("filtermail_http_port", "10082"))
+        self.filtermail_http_port_incoming = int(
+            params.get("filtermail_http_port_incoming", "10082")
+        )
         self.postfix_reinject_port = int(params.get("postfix_reinject_port", "10025"))
         self.postfix_reinject_port_incoming = int(
             params.get("postfix_reinject_port_incoming", "10026")
@@ -93,6 +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")
 
@@ -106,6 +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().rstrip("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/newemail.py

@@ -2,6 +2,7 @@
 
 """CGI script for creating new accounts."""
 
+import ipaddress
 import json
 import secrets
 import string
@@ -14,6 +15,16 @@ ALPHANUMERIC = string.ascii_lowercase + string.digits
 ALPHANUMERIC_PUNCT = string.ascii_letters + string.digits + string.punctuation
 
 
+def wrap_ip(host):
+    if host.startswith("[") and host.endswith("]"):
+        return host
+    try:
+        ipaddress.ip_address(host)
+        return f"[{host}]"
+    except ValueError:
+        return host
+
+
 def create_newemail_dict(config: Config):
     user = "".join(
         secrets.choice(ALPHANUMERIC) for _ in range(config.username_max_length)
@@ -22,7 +33,7 @@ def create_newemail_dict(config: Config):
         secrets.choice(ALPHANUMERIC_PUNCT)
         for _ in range(config.password_min_length + 3)
     )
-    return dict(email=f"{user}@{config.mail_domain}", password=f"{password}")
+    return dict(email=f"{user}@{wrap_ip(config.mail_domain)}", password=f"{password}")
 
 
 def create_dclogin_url(email, password):

chatmaild/src/chatmaild/quota_expire.py

@@ -0,0 +1,90 @@
+"""
+Quota-triggered per-user mailbox cleanup.
+
+Dovecot calls this script via ``quota_warning``
+when a user crosses the quota threshold.
+The script removes oldest messages first
+to keep the mailbox under a specified target size.
+
+Usage::
+
+    chatmail-quota-expire <target_mb> <mailbox_path>
+
+"""
+
+import sys
+from argparse import ArgumentParser
+from pathlib import Path
+
+from chatmaild.expire import get_file_entry, os_listdir_if_exists
+
+
+def scan_mailbox_messages(mailbox_dir):
+    """Collect FileEntry items from top-level cur/new/tmp only."""
+    mbox = Path(mailbox_dir)
+    messages = []
+    for sub in ("cur", "new", "tmp"):
+        for name in os_listdir_if_exists(mbox / sub):
+            if entry := get_file_entry(str(mbox / sub / name)):
+                messages.append(entry)
+    return messages
+
+
+def expire_to_target(mailbox_dir, target_bytes):
+    """Remove oldest files until total size <= *target_bytes*.
+
+    Returns ``(removed_count, cache_bytes)`` where *cache_bytes*
+    is the size of the deleted ``dovecot.index.cache`` file
+    (0 when the file did not exist).
+    """
+    mbox = Path(mailbox_dir)
+    messages = scan_mailbox_messages(mbox)
+    total_size = sum(m.size for m in messages)
+    removed = 0
+    for count, entry in enumerate(sorted(messages, key=lambda m: m.mtime), 1):
+        if total_size <= target_bytes:
+            break
+        Path(entry.path).unlink(missing_ok=True)
+        total_size -= entry.size
+        removed = count
+
+    (mbox / "maildirsize").unlink(missing_ok=True)
+    cache = mbox / "dovecot.index.cache"
+    try:
+        cache_bytes = cache.stat().st_size
+    except FileNotFoundError:
+        cache_bytes = 0
+    cache.unlink(missing_ok=True)
+    return removed, cache_bytes
+
+
+def main(args=None):
+    """Remove mailbox messages to stay within a megabyte target."""
+    parser = ArgumentParser(description=main.__doc__)
+    parser.add_argument(
+        "target_mb",
+        type=int,
+        help="target mailbox size in megabytes",
+    )
+    parser.add_argument(
+        "mailbox_path",
+        help="path to a user mailbox",
+    )
+    args = parser.parse_args(args)
+
+    target_bytes = args.target_mb * 1024 * 1024
+
+    removed_count, cache_bytes = expire_to_target(args.mailbox_path, target_bytes)
+    if removed_count:
+        user = Path(args.mailbox_path).name
+        cache_mb = cache_bytes / 1024 / 1024
+        print(
+            f"quota-expire: removed {removed_count} message(s) from {user}"
+            f" cache={cache_mb:.1f}MB",
+            file=sys.stderr,
+        )
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

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_newmail.py

@@ -19,6 +19,12 @@ def test_create_newemail_dict(example_config):
     assert ac1["password"] != ac2["password"]
 
 
+def test_create_newemail_dict_ip(make_config):
+    config = make_config("1.2.3.4")
+    ac = create_newemail_dict(config)
+    assert ac["email"].endswith("@[1.2.3.4]")
+
+
 def test_create_dclogin_url():
     url = create_dclogin_url("user@example.org", "p@ss w+rd")
     assert url.startswith("dclogin:")

chatmaild/src/chatmaild/tests/test_quota_expire.py

@@ -0,0 +1,73 @@
+import os
+import time
+
+from chatmaild.quota_expire import expire_to_target, main, scan_mailbox_messages
+
+MB = 1024 * 1024
+
+
+def _create_message(basedir, relpath, size, days_old=0):
+    path = basedir / relpath
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_bytes(b"x" * size)
+    mtime = time.time() - days_old * 86400
+    os.utime(path, (mtime, mtime))
+    return path
+
+
+def test_scan_cur_new_tmp(tmp_path):
+    _create_message(tmp_path, "cur/msg1", 100)
+    _create_message(tmp_path, "new/msg2", 200)
+    _create_message(tmp_path, "tmp/msg3", 300)
+    assert len(scan_mailbox_messages(str(tmp_path))) == 3
+
+
+def test_scan_ignores_subfolders(tmp_path):
+    _create_message(tmp_path, "cur/a", 10)
+    _create_message(tmp_path, ".DeltaChat/cur/b", 20)
+    assert len(scan_mailbox_messages(str(tmp_path))) == 1
+
+
+def test_removes_to_target(tmp_path):
+    for i in range(15):
+        _create_message(tmp_path, f"cur/msg{i:02d}", MB, days_old=i + 1)
+    removed, _ = expire_to_target(str(tmp_path), 10 * MB)
+    assert removed == 5
+    assert len(scan_mailbox_messages(str(tmp_path))) == 10
+
+
+def test_removes_oldest_first(tmp_path):
+    _create_message(tmp_path, "cur/old_small", MB, days_old=30)
+    _create_message(tmp_path, "cur/new_huge", 10 * MB, days_old=1)
+    # the 10MB file is kept, the 1MB file is removed because it's older
+    removed, _ = expire_to_target(str(tmp_path), 10 * MB)
+    assert removed == 1
+    assert not (tmp_path / "cur/old_small").exists()
+    assert (tmp_path / "cur/new_huge").exists()
+
+
+def test_exact_limit(tmp_path):
+    _create_message(tmp_path, "cur/msg1", 5 * MB)
+    removed, _ = expire_to_target(str(tmp_path), 5 * MB)
+    assert removed == 0
+
+
+def test_removes_stale_caches(tmp_path):
+    _create_message(tmp_path, "cur/msg1", 2 * MB, days_old=5)
+    (tmp_path / "maildirsize").write_text("x")
+    (tmp_path / "dovecot.index.cache").write_bytes(b"y" * 4096)
+    removed, cache_bytes = expire_to_target(str(tmp_path), MB)
+    assert removed == 1
+    assert cache_bytes == 4096
+    assert not (tmp_path / "maildirsize").exists()
+    assert not (tmp_path / "dovecot.index.cache").exists()
+
+
+def test_logging_output_is_mtail_compatible(tmp_path, capsys):
+    mbox = tmp_path / "user@example.org"
+    _create_message(mbox, "cur/msg1", 2 * MB, days_old=5)
+    (mbox / "dovecot.index.cache").write_bytes(b"c" * 2 * MB)
+    main([str(1), str(mbox)])
+    _, err = capsys.readouterr()
+    assert "quota-expire: removed 1 message(s) from user@example.org" in err
+    assert "cache=2.0MB" in err

cmdeploy/src/cmdeploy/deployers.py

@@ -158,7 +158,7 @@ class UnboundDeployer(Deployer):
         with blocked_service_startup():
             apt.packages(
                 name="Install unbound",
-                packages=["unbound", "unbound-anchor", "dnsutils"],
+                packages=["unbound", "unbound-anchor", "dnsutils", "resolvconf"],
             )
 
     def configure(self):

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -4,7 +4,7 @@ import urllib.request
 from chatmaild.config import Config
 from pyinfra import host
 from pyinfra.facts.deb import DebPackages
-from pyinfra.facts.server import Arch, Sysctl
+from pyinfra.facts.server import Arch, Command, Sysctl
 from pyinfra.operations import apt, files, server, systemd
 
 from cmdeploy.basedeploy import (
@@ -80,6 +80,17 @@ class DovecotDeployer(Deployer):
     def activate(self):
         activate_remote_units(self.units)
 
+        # Detect stale binary: package installed but service still runs old (deleted) binary.
+        if not self.disable_mail and not self.need_restart:
+            stale = host.get_fact(
+                Command,
+                'pid=$(systemctl show -p MainPID --value dovecot.service 2>/dev/null);'
+                ' [ "${pid:-0}" != "0" ] && readlink "/proc/$pid/exe" 2>/dev/null | grep -q "(deleted)"'
+                " && echo STALE || true",
+            )
+            if stale == "STALE":
+                self.need_restart = True
+
         restart = False if self.disable_mail else self.need_restart
 
         systemd.service(

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

@@ -133,6 +133,11 @@ protocol lmtp {
   # mail_lua and push_notification_lua are needed for Lua push notification handler.
   # <https://doc.dovecot.org/2.3/configuration_manual/push_notification/#configuration>
   mail_plugins = $mail_plugins mail_lua notify push_notification push_notification_lua
+
+  # Disable fsync for LMTP. May lose delivered message,
+  # but unlikely to cause problems with multiple relays.
+  # https://doc.dovecot.org/2.3/admin_manual/mailbox_formats/#fsyncing
+  mail_fsync = never
 }
 
 plugin {
@@ -144,12 +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
+
+  # Inflate the dovecot-visible quota so that Delta Chat clients
+  # (which warn at 80% of the IMAP-reported limit) never see
+  # quota warnings -- expire kicks in well before that point.
+  quota_rule = *:storage={{ config.max_mailbox_size_mb * 140 // 100 }}M
+
+  # Trigger when usage reaches the configured max_mailbox_size
+  # (72% of inflated = ~100% of configured), then expire oldest
+  # messages down to 80% of the configured max_mailbox_size.
+  quota_warning = storage=72%% quota-warning {{ config.max_mailbox_size_mb * 80 // 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 {
+  }
 }
 
 # push_notification configuration
@@ -252,6 +271,9 @@ protocol imap {
   # sort -sn <(sed 's/ / C: /' *.in) <(sed 's/ / S: /' cat *.out)
 
   rawlog_dir = %h 
+
+  # Disable fsync for IMAP. May lose IMAP changes like setting flags. 
+  mail_fsync = never
 } 
 {% endif %}
 

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/nginx/nginx.conf.j2

@@ -74,7 +74,7 @@ http {
 		access_log syslog:server=unix:/dev/log,facility=local7;
 
 		location /mxdeliv/ {
-		    proxy_pass http://127.0.0.1:{{ config.filtermail_http_port }};
+		    proxy_pass http://127.0.0.1:{{ config.filtermail_http_port_incoming }};
 		}
 
 		location / {

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

@@ -88,9 +88,12 @@ class TestEndToEndDeltaChat:
             return int(float(number) * units[unit])
 
         quota = parse_size_limit(chatmail_config.max_mailbox_size)
+        # Dovecot quota is inflated to 140% of the configured limit
+        # so that quota-expire keeps users below the warning threshold.
+        dovecot_quota = quota * 140 // 100
 
         lp.sec(f"filling remote inbox for {user}")
-        fn = f"7743102289.M843172P2484002.c20,S={quota},W=2398:2,"
+        fn = f"7743102289.M843172P2484002.c20,S={dovecot_quota},W=2398:2,"
         path = chatmail_config.mailboxes_dir.joinpath(user, "cur", fn)
         sshexec = get_sshexec(sshdomain)
         sshexec(call=rshell.write_numbytes, kwargs=dict(path=str(path), num=120))

cmdeploy/src/cmdeploy/tests/plugin.py

@@ -1,4 +1,5 @@
 import imaplib
+import ipaddress
 import itertools
 import os
 import random
@@ -14,6 +15,14 @@ from chatmaild.config import read_config
 conftestdir = Path(__file__).parent
 
 
+def _is_ip(domain):
+    try:
+        ipaddress.ip_address(domain)
+        return True
+    except ValueError:
+        return False
+
+
 def pytest_addoption(parser):
     parser.addoption(
         "--slow", action="store_true", default=False, help="also run slow tests"
@@ -282,6 +291,7 @@ def gencreds(chatmail_config):
 
     def gen(domain=None):
         domain = domain if domain else chatmail_config.mail_domain
+        addr_domain = f"[{domain}]" if _is_ip(domain) else domain
         while 1:
             num = next(count)
             alphanumeric = "abcdefghijklmnopqrstuvwxyz1234567890"
@@ -295,7 +305,7 @@ def gencreds(chatmail_config):
             password = "".join(
                 random.choices(alphanumeric, k=chatmail_config.password_min_length)
             )
-            yield f"{user}@{domain}", f"{password}"
+            yield f"{user}@{addr_domain}", f"{password}"
 
     return lambda domain=None: next(gen(domain))
 
@@ -344,9 +354,22 @@ class ChatmailACFactory:
         accounts = []
         for _ in range(num):
             account = self.dc.add_account()
-            future = account.add_or_update_transport.future(
-                self._make_transport(domain)
-            )
+            addr, password = self.gencreds(domain)
+            if _is_ip(domain):
+                # Use DCLOGIN scheme with explicit server hosts,
+                # matching how madmail presents its addresses to users.
+                qr = (
+                    f"dclogin:{addr}"
+                    f"?p={password}&v=1"
+                    f"&ih={domain}&ip=993"
+                    f"&sh={domain}&sp=465"
+                    f"&ic=3&ss=default"
+                )
+                future = account.add_transport_from_qr.future(qr)
+            else:
+                future = account.add_or_update_transport.future(
+                    self._make_transport(domain)
+                )
             futures.append(future)
 
             # ensure messages stay in INBOX so that they can be

cmdeploy/src/cmdeploy/tests/test_dovecot_deployer.py

@@ -2,9 +2,9 @@ from contextlib import nullcontext
 from types import SimpleNamespace
 
 import pytest
+from pyinfra.facts.deb import DebPackages
 
 from cmdeploy.dovecot import deployer as dovecot_deployer
-from pyinfra.facts.deb import DebPackages
 
 
 def make_host(*fact_pairs):

doc/source/overview.rst

@@ -102,8 +102,15 @@ 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 when a
+   mailbox exceeds ``max_mailbox_size``.
+   It removes the oldest messages
+   until usage drops to a safe level.
 
 -  `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
@@ -156,6 +163,8 @@ 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;