syslog-ng[8]: REDIS server error during connection; driver='d_redis_ui_log#0', error='Temporary failure in name resolution', time_reopen='60'

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Summary

I updated mailcow to the latest version 2022-01a, there was some issues, can't remember what, but after a restart, everything seemed to work fine.

I updated my server like so:

cd /opt/mailcow-dockerized/; ./update.sh --force
docker system prune -f
apt -q full-upgrade -y --autoremove
reboot

A customer notified me that he could not send me an e-mail, I checked the server, and everything was down because of Redis.

I rebooted several times, but no luck.

Where are the downgrade documentations? I can't seem to find them.

Logs

It looks like Redis got messed up somehow, according to several logs:

mcuadros/ofelia:latest

Could not connect to Redis at redis:6379: Temporary failure in name resolution
Could not connect to Redis at redis:6379: Temporary failure in name resolution
Could not connect to Redis at redis:6379: Temporary failure in name resolution
Could not connect to Redis at redis:6379: Temporary failure in name resolution
2022-02-19T17:35:33.99+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "dovecot_trim_logs" (8925c8a6273f)] Finished in "3m0.980763704s", failed: false, skipped: false, error: none
2022-02-19T17:35:34.251+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "sogo_ealarms" (71423a8c3eac)] Finished in "1.231448802s", failed: false, skipped: false, error: none
2022-02-19T17:35:34.352+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "sogo_sessions" (d6379ba4b9fc)] Finished in "1.323126023s", failed: false, skipped: false, error: none
2022-02-19T17:35:34.38+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "sogo_eautoreply" (1e3984d098e8)] Finished in "1.339657836s", failed: false, skipped: false, error: none
2022-02-19T17:35:35.134+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "dovecot_quarantine" (eff37f658629)] StdOut: /tmp/quarantine_notify.pid already exists, exiting
2022-02-19T17:35:35.135+01:00 [32m common.go:125 ▶ NOTICE[0m [Job "dovecot_quarantine" (eff37f658629)] Finished in "2.125000392s", failed: false, skipped: false, error: none

mailcow/netfilter:1.46

Error in atexit._run_exitfuncs:
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/server.py", line 319, in watch
Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 800, in read_response
    for item in pubsub.listen():
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1560, in listen
    response = self.handle_message(self.parse_response(block=True))
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1438, in parse_response
    response = self._execute(conn, conn.read_response)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1420, in _execute
    return conn.retry.call_with_retry(
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 44, in call_with_retry
    response = self._parser.read_response(disable_decoding=disable_decoding)
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 320, in read_response
    raw = self._buffer.readline()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 251, in readline
    self._read_from_socket()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 194, in _read_from_socket
    data = self._sock.recv(socket_read_size)
ConnectionResetError: [Errno 104] Connection reset by peer

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1176, in execute_command
    return conn.retry.call_with_retry(
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 44, in call_with_retry
    fail(error)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1422, in <lambda>
    lambda error: self._disconnect_raise_connect(conn, error),
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1409, in _disconnect_raise_connect
    raise error
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 41, in call_with_retry
    return do()
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1421, in <lambda>
    lambda: command(*args, **kwargs),
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 800, in read_response
    response = self._parser.read_response(disable_decoding=disable_decoding)
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 320, in read_response
    raw = self._buffer.readline()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 251, in readline
    self._read_from_socket()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 197, in _read_from_socket
    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
redis.exceptions.ConnectionError: Connection closed by server.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 1364, in get_connection
    if connection.can_read():
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 795, in can_read
    return self._parser.can_read(timeout)
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 317, in can_read
    return self._buffer and self._buffer.can_read(timeout)
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 224, in can_read
    return bool(self.length) or self._read_from_socket(
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 197, in _read_from_socket
    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
redis.exceptions.ConnectionError: Connection closed by server.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 607, in connect
    sock = self._connect()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 671, in _connect
    raise err
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 659, in _connect
    sock.connect(socket_address)
ConnectionRefusedError: [Errno 111] Connection refused

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.9/threading.py", line 973, in _bootstrap_inner
    fail(error)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1180, in <lambda>
    lambda error: self._disconnect_raise(conn, error),
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1166, in _disconnect_raise
    raise error
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 41, in call_with_retry
    return do()
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1177, in <lambda>
    lambda: self._send_command_parse_response(
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1153, in _send_command_parse_response
    return self.parse_response(conn, command_name, **options)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1192, in parse_response
    response = connection.read_response()
  File "/usr/lib/python3.9/site-packages/redis/connection.py", line 806, in read_response
    raise ConnectionError(
redis.exceptions.ConnectionError: Error while reading from 172.22.1.249:6379 : (104, 'Connection reset by peer')
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/server.py", line 319, in watch
    for item in pubsub.listen():
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1560, in listen
    response = self.handle_message(self.parse_response(block=True))
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1438, in parse_response
    response = self._execute(conn, conn.read_response)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1420, in _execute
    return conn.retry.call_with_retry(
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 44, in call_with_retry
    fail(error)
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1422, in <lambda>
    lambda error: self._disconnect_raise_connect(conn, error),
  File "/usr/lib/python3.9/site-packages/redis/client.py", line 1409, in _disconnect_raise_connect
    raise error
  File "/usr/lib/python3.9/site-packages/redis/retry.py", line 41, in call_with_retry
    return do()
Error 113 connecting to 172.22.1.249:6379. Host is unreachable. - trying again in 3 seconds
... redacted duplicate lines

mailcow/acme:1.81

dig: couldn't get address for 'unbound': failure
... redacted duplicate lines

Could not connect to Redis at redis:6379: Try again
... redacted duplicate lines

Waiting for Redis...
... redacted duplicate lines

mailcow/dovecot:1.159

Feb 18 06:00:44 6a8878a982f0 dovecot: lmtp(35464): Connect from 172.22.1.7
Feb 18 06:00:44 6a8878a982f0 dovecot: lmtp(35464): Disconnect from 172.22.1.7: Logged out (state=MAIL FROM)
Feb 18 06:00:44 6a8878a982f0 dovecot: imap-login: Disconnected: Aborted login by logging out (no auth attempts in 0 secs): user=<>, rip=172.22.1.7, lip=172.22.1.250, TLS, TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
Feb 18 06:00:44 6a8878a982f0 dovecot: imap-login: Disconnected: Aborted login by logging out (no auth attempts in 0 secs): user=<>, rip=172.22.1.7, lip=172.22.1.250
Feb 18 06:00:44 6a8878a982f0 dovecot: managesieve-login: Disconnected: Connection closed (no auth attempts in 0 secs): user=<>, rip=172.22.1.7, lip=172.22.1.250
Feb 18 06:00:44 6a8878a982f0 dovecot: imap(REDACTED_USER@REDACTED_DOMAIN)<34240><UBGYWEPY+rhUaNLS>: Disconnected: Inactivity - no input for 1800 secs in=152 out=2949 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Feb 18 06:01:37 6a8878a982f0 syslog-ng[121]: REDIS server error, suspending; driver='d_redis_f2b_channel#0', error='Name or service not known', time_reopen='60'
Feb 18 06:01:37 6a8878a982f0 syslog-ng[121]: Server disconnected while preparing messages for sending, trying again; driver='d_redis_f2b_channel#0', location='/etc/syslog-ng/syslog-ng.conf:26:3', worker_index='0', batch_size='1'
Feb 18 06:01:37 6a8878a982f0 syslog-ng[121]: REDIS server error, suspending; driver='d_redis_ui_log#0', error='Name or service not known', time_reopen='60'
Feb 18 06:01:37 6a8878a982f0 syslog-ng[121]: Server disconnected while preparing messages for sending, trying again; driver='d_redis_ui_log#0', location='/etc/syslog-ng/syslog-ng.conf:18:3', worker_index='0', batch_size='1'

nginx:mainline-alpine

2022/02/16 00:39:24 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/16 00:39:31 [notice] 1#1: using the "epoll" event method
2022/02/16 00:39:31 [notice] 1#1: nginx/1.21.6
2022/02/16 00:39:31 [notice] 1#1: built by gcc 10.3.1 20211027 (Alpine 10.3.1_git20211027) 
2022/02/16 00:39:31 [notice] 1#1: OS: Linux 5.4.0-91-generic
2022/02/16 00:39:31 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/02/16 00:39:31 [notice] 1#1: start worker processes
2022/02/16 00:39:31 [notice] 1#1: start worker process 23
2022/02/16 00:39:31 [notice] 1#1: start cache manager process 24
2022/02/16 00:39:31 [notice] 1#1: start cache loader process 25
2022/02/16 00:39:33 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.11, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://172.22.1.9:9002", host: "nginx"
2022/02/16 00:39:33 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.11, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://[fd4d:6169:6c63:6f77::c]:9002", host: "nginx"
2022/02/16 00:40:31 [notice] 25#25: http file cache: /tmp 0.000M, bsize: 4096
2022/02/16 00:40:31 [notice] 1#1: signal 17 (SIGCHLD) received from 25
2022/02/16 00:40:31 [notice] 1#1: cache loader process 25 exited with code 0
2022/02/16 00:40:31 [notice] 1#1: signal 29 (SIGIO) received
2022/02/16 00:47:26 [error] 23#23: *596 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 84.104.210.210, server: mail.REDACTED_DOMAIN, request: "REPORT /SOGo/dav/support%40REDACTED_DOMAIN/Calendar/personal/ HTTP/1.1", upstream: "http://172.22.1.248:20000/SOGo/dav/support%40REDACTED_DOMAIN/Calendar/personal/", host: "mail.REDACTED_DOMAIN"
2022/02/16 00:47:26 [error] 23#23: *595 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 84.104.210.210, server: mail.REDACTED_DOMAIN, request: "REPORT /SOGo/dav/REDACTED_USER%40REDACTED_DOMAIN/Calendar/personal/ HTTP/1.1", upstream: "http://172.22.1.248:20000/SOGo/dav/REDACTED_USER%40REDACTED_DOMAIN/Calendar/personal/", host: "mail.REDACTED_DOMAIN"
2022/02/16 00:47:26 [error] 23#23: *594 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 84.104.210.210, server: mail.REDACTED_DOMAIN, request: "REPORT /SOGo/dav/REDACTED_USER%40REDACTED_DOMAIN/Calendar/personal/ HTTP/1.1", upstream: "http://172.22.1.248:20000/SOGo/dav/REDACTED_USER%40REDACTED_DOMAIN/Calendar/personal/", host: "mail.REDACTED_DOMAIN"
2022/02/16 00:49:15 [notice] 1#1: signal 3 (SIGQUIT) received, shutting down
2022/02/16 00:49:15 [notice] 24#24: exiting
2022/02/16 00:49:15 [notice] 23#23: gracefully shutting down
2022/02/16 00:49:15 [notice] 23#23: exiting
2022/02/16 00:49:15 [notice] 1#1: signal 17 (SIGCHLD) received from 24
2022/02/16 00:49:15 [notice] 1#1: cache manager process 24 exited with code 0
2022/02/16 00:49:15 [notice] 1#1: signal 29 (SIGIO) received
2022/02/16 00:49:15 [notice] 23#23: exit
2022/02/16 00:49:15 [notice] 1#1: signal 17 (SIGCHLD) received from 23
2022/02/16 00:49:15 [notice] 1#1: worker process 23 exited with code 0
2022/02/16 00:49:15 [notice] 1#1: exit
2022/02/16 00:49:42 [notice] 1#1: using the "epoll" event method
2022/02/16 00:49:42 [notice] 1#1: nginx/1.21.6
2022/02/16 00:49:42 [notice] 1#1: built by gcc 10.3.1 20211027 (Alpine 10.3.1_git20211027) 
2022/02/16 00:49:42 [notice] 1#1: OS: Linux 5.4.0-91-generic
2022/02/16 00:49:42 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/02/16 00:49:42 [notice] 1#1: start worker processes
2022/02/16 00:49:42 [notice] 1#1: start worker process 23
2022/02/16 00:49:42 [notice] 1#1: start cache manager process 24
2022/02/16 00:49:42 [notice] 1#1: start cache loader process 25
2022/02/16 00:49:46 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.4, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://172.22.1.9:9002", host: "nginx"
2022/02/16 00:49:46 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.4, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://[fd4d:6169:6c63:6f77::d]:9002", host: "nginx"
2022/02/16 00:49:55 [error] 23#23: *7 no live upstreams while connecting to upstream, client: 84.104.210.210, server: mail.REDACTED_DOMAIN, request: "GET /user HTTP/2.0", upstream: "fastcgi://phpfpm", host: "mail.REDACTED_DOMAIN", referrer: "https://mail.REDACTED_DOMAIN/"
2022/02/16 00:50:43 [notice] 25#25: http file cache: /tmp 0.000M, bsize: 4096
2022/02/16 00:50:43 [notice] 1#1: signal 17 (SIGCHLD) received from 25
2022/02/16 00:50:43 [notice] 1#1: cache loader process 25 exited with code 0
2022/02/16 00:50:43 [notice] 1#1: signal 29 (SIGIO) received
2022/02/16 00:52:05 [notice] 1#1: signal 3 (SIGQUIT) received, shutting down
2022/02/16 00:52:05 [notice] 24#24: exiting
2022/02/16 00:52:05 [notice] 23#23: gracefully shutting down
2022/02/16 00:52:05 [notice] 1#1: signal 17 (SIGCHLD) received from 24
2022/02/16 00:52:05 [notice] 1#1: cache manager process 24 exited with code 0
2022/02/16 00:52:05 [notice] 1#1: signal 29 (SIGIO) received
2022/02/16 00:52:05 [notice] 23#23: exiting
2022/02/16 00:52:05 [notice] 23#23: exit
2022/02/16 00:52:05 [notice] 1#1: signal 17 (SIGCHLD) received from 23
2022/02/16 00:52:05 [notice] 1#1: worker process 23 exited with code 0
2022/02/16 00:52:05 [notice] 1#1: exit
2022/02/16 00:52:51 [notice] 1#1: using the "epoll" event method
2022/02/16 00:52:51 [notice] 1#1: nginx/1.21.6
2022/02/16 00:52:51 [notice] 1#1: built by gcc 10.3.1 20211027 (Alpine 10.3.1_git20211027) 
2022/02/16 00:52:51 [notice] 1#1: OS: Linux 5.4.0-99-generic
2022/02/16 00:52:51 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/02/16 00:52:51 [notice] 1#1: start worker processes
2022/02/16 00:52:51 [notice] 1#1: start worker process 23
2022/02/16 00:52:51 [notice] 1#1: start cache manager process 24
2022/02/16 00:52:51 [notice] 1#1: start cache loader process 25
2022/02/16 00:52:54 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.9, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://172.22.1.13:9002", host: "nginx"
2022/02/16 00:52:54 [error] 23#23: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 172.22.1.9, server: mail.REDACTED_DOMAIN, request: "GET / HTTP/1.1", upstream: "fastcgi://[fd4d:6169:6c63:6f77::12]:9002", host: "nginx"
2022/02/16 00:53:51 [notice] 25#25: http file cache: /tmp 0.000M, bsize: 4096
2022/02/16 00:53:51 [notice] 1#1: signal 17 (SIGCHLD) received from 25
2022/02/16 00:53:51 [notice] 1#1: cache loader process 25 exited with code 0
2022/02/16 00:53:51 [notice] 1#1: signal 29 (SIGIO) received
2022/02/16 02:59:23 [crit] 23#23: *1329 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 134.122.112.12, server: 0.0.0.0:443
2022/02/16 05:55:17 [crit] 23#23: *2987 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 163.172.158.4, server: 0.0.0.0:443
2022/02/16 15:51:38 [crit] 23#23: *14072 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 192.241.212.128, server: 0.0.0.0:443
2022/02/16 21:04:20 [crit] 23#23: *23419 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 117.50.38.174, server: 0.0.0.0:443
2022/02/17 04:40:32 [crit] 23#23: *32251 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 185.220.100.244, server: 0.0.0.0:443
2022/02/17 09:00:57 [crit] 23#23: *34855 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 216.218.206.66, server: 0.0.0.0:443
2022/02/17 12:29:12 [error] 23#23: *38210 open() "/web/ HTTP/1.1
Host: xss_test

" failed (2: No such file or directory), client: 104.168.102.21, server: mail.REDACTED_DOMAIN, request: "GET /%20HTTP/1.1%0d%0aHost:%20xss_test%0d%0a%0d%0a HTTP/1.1", host: "23.88.59.78"
2022/02/17 16:19:24 [error] 23#23: *1560 FastCGI sent in stderr: "PHP message: RCPT RESOVLER: http pipe: query REDACTED_USER@REDACTED_DOMAIN as username from mailbox
PHP message: RCPT RESOVLER: http pipe: mailbox found: REDACTED_USER@REDACTED_DOMAIN
PHP message: RCPT RESOVLER: http pipe: goto array count on loop #1 is 0
PHP message: NOTIFY: pushover pipe: processing pushover message for rcpt REDACTED_USER@REDACTED_DOMAIN" while reading response header from upstream, client: 172.22.1.2, server: _, request: "POST /pushover.php HTTP/1.1", upstream: "fastcgi://172.22.1.8:9001", host: "nginx"
2022/02/17 16:20:07 [error] 23#23: *1636 FastCGI sent in stderr: "PHP message: RCPT RESOVLER: http pipe: query REDACTED_USER@REDACTED_DOMAIN as username from mailbox
PHP message: RCPT RESOVLER: http pipe: mailbox found: REDACTED_USER@REDACTED_DOMAIN
PHP message: RCPT RESOVLER: http pipe: goto array count on loop #1 is 0
PHP message: NOTIFY: pushover pipe: processing pushover message for rcpt REDACTED_USER@REDACTED_DOMAIN" while reading response header from upstream, client: 172.22.1.2, server: _, request: "POST /pushover.php HTTP/1.1", upstream: "fastcgi://172.22.1.8:9001", host: "nginx"
2022/02/18 05:39:34 [crit] 23#23: *27141 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 165.154.6.57, server: 0.0.0.0:443
2022/02/19 17:16:02 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:16:09 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:16:18 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:16:30 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:16:49 [emerg] 17#17: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:17:20 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:18:17 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:19:23 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:20:29 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:21:35 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:22:41 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:23:46 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:24:52 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:25:58 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:27:04 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:28:09 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:29:15 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:30:21 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:31:27 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:32:33 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:33:39 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
2022/02/19 17:34:45 [emerg] 18#18: host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: [emerg] host not found in upstream "rspamd" in /etc/nginx/conf.d/includes/site-defaults.conf:111
nginx: configuration file /etc/nginx/nginx.conf test failed
127.0.0.1 - REDACTED_USER@REDACTED_DOMAIN [18/Feb/2022:23:58:26 +0100] "GET /sogo-auth HTTP/1.0" 200 182 "-" "Evolution/3.42.4"
84.104.210.210 - REDACTED_USER@REDACTED_DOMAIN [18/Feb/2022:23:58:26 +0100] "OPTIONS /SOGo/dav/REDACTED_USER%40REDACTED_DOMAIN/Calendar/personal/ HTTP/1.1" 401 0 "-" "Evolution/3.42.4"
172.22.1.7 - - [18/Feb/2022:23:58:43 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [18/Feb/2022:23:59:30 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:00:33 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:01:45 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:02:28 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:03:03 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:04:06 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"
172.22.1.7 - - [19/Feb/2022:00:05:01 +0100] "GET / HTTP/1.1" 200 15 "-" "check_http/v (nagios-plugins 2.3.3)"

mailcow/olefy:1.8.1

olefy INFO <module> olefy listen address: ['0.0.0.0'] (type: <class 'list'>)
olefy INFO <module> olefy listen port: 10055
olefy INFO <module> olefy tmp dir: /tmp
olefy INFO <module> olefy python path: /usr/bin/python3
olefy INFO <module> olefy olvba path: /usr/bin/olevba3
olefy INFO <module> olefy log level: 20
olefy INFO <module> olefy min file length: 500
olefy INFO <module> olefy delete tmp file: 1
olefy INFO <module> olefy delete tmp file when failed: 1
olefy INFO <module> serving on ('0.0.0.0', 10055)

memcached:alpine

Signal handled: Terminated.
Signal handled: Terminated.
Signal handled: Terminated.
Signal handled: Terminated.
Signal handled: Terminated.
Signal handled: Terminated.

mailcow/sogo:1.106

[2022-02-16T00:39:22.855395] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;
[2022-02-16T00:47:38.377448] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;
[2022-02-16T00:49:46.618844] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;
[2022-02-16T00:52:52.007338] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;
[2022-02-19T17:31:46.452016] WARNING: With use-dns(no), dns-cache() will be forced to 'no' too!;
Feb 19 17:31:47 ae062faf5702 sogod [60]: <0x0x55fdd5c92df0[WOHttpAdaptor]> notified the watchdog that we are ready
Feb 19 17:31:47 ae062faf5702 sogod [69]: <0x0x55fdd5c638f0[WOHttpAdaptor]> notified the watchdog that we are ready
Feb 19 17:31:47 ae062faf5702 sogod [66]: <0x0x55fdd5c8b4b0[WOHttpAdaptor]> notified the watchdog that we are ready
Feb 19 17:31:47 ae062faf5702 sogod [67]: <0x0x55fdd5c8b4b0[WOHttpAdaptor]> notified the watchdog that we are ready
Feb 19 17:31:46 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_ui_log#0', error='Temporary failure in name resolution', time_reopen='60'
Feb 19 17:31:46 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_f2b_channel#0', error='Temporary failure in name resolution', time_reopen='60'
Feb 19 17:33:06 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_ui_log#0', error='Temporary failure in name resolution', time_reopen='60'
Feb 19 17:33:06 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_f2b_channel#0', error='Temporary failure in name resolution', time_reopen='60'
Feb 19 17:34:26 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_ui_log#0', error='Temporary failure in name resolution', time_reopen='60'
Feb 19 17:34:26 ae062faf5702 syslog-ng[8]: REDIS server error during connection; driver='d_redis_f2b_channel#0', error='Temporary failure in name resolution', time_reopen='60'

mailcow/watchdog:1.96

Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...
Waiting for Redis...

Reproduction

Follow the above mentioned update steps above, to the latest mailcow version: 2022-01a

System information

Question	Answer
My operating system	Ubuntu 20.04.4 LTS
Is Apparmor, SELinux or similar active?	No.
Virtualization technlogy (KVM, VMware, Xen, etc - LXC and OpenVZ are not supported	VMware
Server/VM specifications (Memory, CPU Cores)	1 Core, 2GiB ram,
Docker Version (`docker version`)	20.10.12
Docker-Compose Version (`docker-compose version`)	1.29.2
Reverse proxy (custom solution)	standard mailcow installation

Output of git diff origin/master, any other changes to the code? If so, please post them.


diff --git a/data/conf/postfix/main.cf b/data/conf/postfix/main.cf
index a445b60c..a599ef99 100644
--- a/data/conf/postfix/main.cf
+++ b/data/conf/postfix/main.cf
@@ -198,3 +198,6 @@ parent_domain_matches_subdomains = debug_peer_list,fast_flush_domains,mynetworks

# DO NOT EDIT ANYTHING BELOW #
# User overrides #

+myhostname = mail.eurobytes.eu
diff --git a/docker-compose.yml b/docker-compose.yml index d706d2dc..a5df0bc3 100644 --- a/docker-compose.yml +++ b/docker-compose.yml @@ -577,36 +577,6 @@ services: aliases:
- ofelia
ipv6nat-mailcow:
depends_on:
- unbound-mailcow
- mysql-mailcow
- redis-mailcow
- clamd-mailcow
- rspamd-mailcow
- php-fpm-mailcow
- sogo-mailcow
- dovecot-mailcow
- postfix-mailcow
- memcached-mailcow
- nginx-mailcow
- acme-mailcow
- netfilter-mailcow
- watchdog-mailcow
- dockerapi-mailcow
- solr-mailcow
environment:
- TZ=${TZ}
image: robbertkl/ipv6nat
security_opt:
- label=disable
restart: always
privileged: true
network_mode: "host"
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
- /lib/modules:/lib/modules:ro
networks: mailcow-network: driver: bridge
All third-party firewalls and custom iptables rules are unsupported. Please check the Docker docs about how to use Docker with your own ruleset. Nevertheless, iptabels output can help us to help you: iptables -L -vn, ip6tables -L -vn, iptables -L -vn -t nat and ip6tables -L -vn -t nat.

Hereby all the IP tables rules:

iptables -L -vn

Chain INPUT (policy ACCEPT 115 packets, 8176 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy DROP 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
  794 66981 DOCKER-USER  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
  794 66981 DOCKER-ISOLATION-STAGE-1  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
    0     0 DOCKER     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  docker0 docker0  0.0.0.0/0            0.0.0.0/0           
   64 30461 ACCEPT     all  --  *      br-mailcow  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
  367 22000 DOCKER     all  --  *      br-mailcow  0.0.0.0/0            0.0.0.0/0           
  363 14520 ACCEPT     all  --  br-mailcow !br-mailcow  0.0.0.0/0            0.0.0.0/0           
    1    60 ACCEPT     all  --  br-mailcow br-mailcow  0.0.0.0/0            0.0.0.0/0           

Chain OUTPUT (policy ACCEPT 121 packets, 81606 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:12345
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:4190
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.6           tcp dpt:3306
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:995
  333 19980 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:993
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.11          tcp dpt:8983
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:143
    0     0 ACCEPT     tcp  --  !br-mailcow br-mailcow  0.0.0.0/0            172.22.1.250         tcp dpt:110

Chain DOCKER-ISOLATION-STAGE-1 (1 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER-ISOLATION-STAGE-2  all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0           
  363 14520 DOCKER-ISOLATION-STAGE-2  all  --  br-mailcow !br-mailcow  0.0.0.0/0            0.0.0.0/0           
  794 66981 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0           

Chain DOCKER-ISOLATION-STAGE-2 (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DROP       all  --  *      docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 DROP       all  --  *      br-mailcow  0.0.0.0/0            0.0.0.0/0           
  363 14520 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0           

Chain DOCKER-USER (1 references)
 pkts bytes target     prot opt in     out     source               destination         
  794 66981 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0

ip6tables -L -vn

Chain INPUT (policy ACCEPT 1 packets, 56 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy DROP 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
 6819  537K DOCKER-ISOLATION-STAGE-1  all      *      *       ::/0                 ::/0                
    0     0 ACCEPT     all      *      docker0  ::/0                 ::/0                 ctstate RELATED,ESTABLISHED
    0     0 DOCKER     all      *      docker0  ::/0                 ::/0                
    0     0 ACCEPT     all      docker0 !docker0  ::/0                 ::/0                
    0     0 ACCEPT     all      docker0 docker0  ::/0                 ::/0                
    0     0 ACCEPT     all      *      br-mailcow  ::/0                 ::/0                 ctstate RELATED,ESTABLISHED
 6760  533K DOCKER     all      *      br-mailcow  ::/0                 ::/0                
    0     0 ACCEPT     all      br-mailcow !br-mailcow  ::/0                 ::/0                
 6760  533K ACCEPT     all      br-mailcow br-mailcow  ::/0                 ::/0                

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 ACCEPT     tcp      !br-mailcow br-mailcow  ::/0                 fd4d:6169:6c63:6f77::5  tcp dpt:4190
    0     0 ACCEPT     tcp      !br-mailcow br-mailcow  ::/0                 fd4d:6169:6c63:6f77::5  tcp dpt:995
    0     0 ACCEPT     tcp      !br-mailcow br-mailcow  ::/0                 fd4d:6169:6c63:6f77::5  tcp dpt:993
    0     0 ACCEPT     tcp      !br-mailcow br-mailcow  ::/0                 fd4d:6169:6c63:6f77::5  tcp dpt:143
    0     0 ACCEPT     tcp      !br-mailcow br-mailcow  ::/0                 fd4d:6169:6c63:6f77::5  tcp dpt:110

Chain DOCKER-ISOLATION-STAGE-1 (1 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER-ISOLATION-STAGE-2  all      docker0 !docker0  ::/0                 ::/0                
    0     0 DOCKER-ISOLATION-STAGE-2  all      br-mailcow !br-mailcow  ::/0                 ::/0                
 6819  537K RETURN     all      *      *       ::/0                 ::/0                

Chain DOCKER-ISOLATION-STAGE-2 (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DROP       all      *      docker0  ::/0                 ::/0                
    0     0 DROP       all      *      br-mailcow  ::/0                 ::/0                
    0     0 RETURN     all      *      *       ::/0                 ::/0

iptables -L -vn -t nat

Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
  652 38844 DOCKER     all  --  *      *       0.0.0.0/0            0.0.0.0/0            ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 10 packets, 600 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER     all  --  *      *       0.0.0.0/0           !127.0.0.0/8          ADDRTYPE match dst-type LOCAL

Chain POSTROUTING (policy ACCEPT 10 packets, 600 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 MASQUERADE  all  --  *      !docker0  172.17.0.0/16        0.0.0.0/0           
    0     0 MASQUERADE  all  --  *      !br-mailcow  172.22.1.0/24        0.0.0.0/0           
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:12345
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:4190
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.6           172.22.1.6           tcp dpt:3306
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:995
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:993
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.11          172.22.1.11          tcp dpt:8983
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:143
    0     0 MASQUERADE  tcp  --  *      *       172.22.1.250         172.22.1.250         tcp dpt:110

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 RETURN     all  --  docker0 *       0.0.0.0/0            0.0.0.0/0           
    0     0 RETURN     all  --  br-mailcow *       0.0.0.0/0            0.0.0.0/0           
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            127.0.0.1            tcp dpt:19991 to:172.22.1.250:12345
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            0.0.0.0/0            tcp dpt:4190 to:172.22.1.250:4190
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            127.0.0.1            tcp dpt:13306 to:172.22.1.6:3306
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            0.0.0.0/0            tcp dpt:995 to:172.22.1.250:995
  333 19980 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            0.0.0.0/0            tcp dpt:993 to:172.22.1.250:993
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            127.0.0.1            tcp dpt:18983 to:172.22.1.11:8983
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            0.0.0.0/0            tcp dpt:143 to:172.22.1.250:143
    0     0 DNAT       tcp  --  !br-mailcow *       0.0.0.0/0            0.0.0.0/0            tcp dpt:110 to:172.22.1.250:110

ip6tables -L -vn -t nat

Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER     all      *      *       ::/0                 ::/0                 ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER     all      *      *       ::/0                !::1                  ADDRTYPE match dst-type LOCAL

Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 MASQUERADE  all      *      !docker0  fd00:dead:beef:c0::/80  ::/0                
    0     0 MASQUERADE  all      *      !br-mailcow  fd4d:6169:6c63:6f77::/64  ::/0                
    0     0 MASQUERADE  tcp      *      *       fd4d:6169:6c63:6f77::5  fd4d:6169:6c63:6f77::5  tcp dpt:4190
    0     0 MASQUERADE  tcp      *      *       fd4d:6169:6c63:6f77::5  fd4d:6169:6c63:6f77::5  tcp dpt:995
    0     0 MASQUERADE  tcp      *      *       fd4d:6169:6c63:6f77::5  fd4d:6169:6c63:6f77::5  tcp dpt:993
    0     0 MASQUERADE  tcp      *      *       fd4d:6169:6c63:6f77::5  fd4d:6169:6c63:6f77::5  tcp dpt:143
    0     0 MASQUERADE  tcp      *      *       fd4d:6169:6c63:6f77::5  fd4d:6169:6c63:6f77::5  tcp dpt:110

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 RETURN     all      docker0 *       ::/0                 ::/0                
    0     0 RETURN     all      br-mailcow *       ::/0                 ::/0                
    0     0 DNAT       tcp      !br-mailcow *       ::/0                 ::/0                 tcp dpt:4190 to:[fd4d:6169:6c63:6f77::5]:4190
    0     0 DNAT       tcp      !br-mailcow *       ::/0                 ::/0                 tcp dpt:995 to:[fd4d:6169:6c63:6f77::5]:995
    0     0 DNAT       tcp      !br-mailcow *       ::/0                 ::/0                 tcp dpt:993 to:[fd4d:6169:6c63:6f77::5]:993
    0     0 DNAT       tcp      !br-mailcow *       ::/0                 ::/0                 tcp dpt:143 to:[fd4d:6169:6c63:6f77::5]:143
    0     0 DNAT       tcp      !br-mailcow *       ::/0                 ::/0                 tcp dpt:110 to:[fd4d:6169:6c63:6f77::5]:110

DNS problems? Please run docker exec -it $(docker ps -qf name=acme-mailcow) dig +short stackoverflow.com @172.22.1.254 (set the IP accordingly, if you changed the internal mailcow network) and post the output.

;; connection timed out; no servers could be reached - the first time around, after playing with some different IP adresses it worked:

docker exec -it $(docker ps -qf name=acme-mailcow) dig +short stackoverflow.com @205.251.193.102

151.101.193.69
151.101.129.69
151.101.65.69
151.101.1.69

mailcow / mailcow-dockerized