Hello ZhangHuangbin,
thank you for the reply here are the logs from var/log/maillog:
2025-12-13T04:06:06.054080+00:00 mail amavis[2527]: Using primary internal av scanner code for clamav-socket
2025-12-13T04:06:42.669585+00:00 mail roundcube: <s9l8o76j> Successful login for csr@imagodvds.su (ID: 6) from 94.197.128.17 in session s9l8o76jang0g13h
2025-12-13T04:06:50.218580+00:00 mail postfix/postscreen[2626]: CONNECT from [103.168.172.156]:34065 to [217.154.37.167]:25
2025-12-13T04:06:50.319712+00:00 mail postfix/postscreen[2626]: PASS OLD [103.168.172.156]:34065
2025-12-13T04:06:50.361989+00:00 mail postfix/smtpd[2629]: connect from fhigh-a5-smtp.messagingengine.com[103.168.172.156]
2025-12-13T04:06:50.445743+00:00 mail postfix/smtpd[2629]: discarding EHLO keywords: CHUNKING
2025-12-13T04:06:50.683414+00:00 mail postfix/smtpd[2629]: Anonymous TLS connection established from fhigh-a5-smtp.messagingengine.com[103.168.172.156]: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256
2025-12-13T04:06:50.761466+00:00 mail postfix/smtpd[2629]: discarding EHLO keywords: CHUNKING
2025-12-13T04:06:50.909227+00:00 mail postfix/smtpd[2629]: 4dSt7G6SBjz25H8: client=fhigh-a5-smtp.messagingengine.com[103.168.172.156]
2025-12-13T04:06:50.991486+00:00 mail postfix/cleanup[2651]: 4dSt7G6SBjz25H8: message-id=<736cf22b-258e-4660-9e45-a71fcac5c63a@app.fastmail.com>
2025-12-13T04:06:50.992644+00:00 mail postfix/qmgr[1936]: 4dSt7G6SBjz25H8: from=<williamtravers@fastmail.co.uk>, size=4024, nrcpt=1 (queue active)
2025-12-13T04:06:50.992751+00:00 mail postfix/smtpd[2629]: disconnect from fhigh-a5-smtp.messagingengine.com[103.168.172.156] ehlo=2 starttls=1 mail=1 rcpt=1 data=1 quit=1 commands=7
2025-12-13T04:06:51.029034+00:00 mail amavis[2543]: (02543-01) (!)connect_to_sql: unable to connect to DSN 'DBI:mysql:database=amavisd;host=127.0.0.1;port=3306': Access denied for user 'amavisd'@'localhost' (using password: YES)
2025-12-13T04:06:51.029203+00:00 mail amavis[2543]: (02543-01) (!!)TROUBLE in process_request: connect_to_sql: unable to connect to any dataset at /usr/share/perl5/Amavis/Out/SQL/Connection.pm line 255.
2025-12-13T04:06:51.029223+00:00 mail amavis[2543]: (02543-01) (!)Requesting process rundown after fatal error
2025-12-13T04:06:51.038048+00:00 mail postfix/amavis/smtp[2656]: 4dSt7G6SBjz25H8: to=<csr@imagodvds.su>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.18, delays=0.13/0.02/0/0.02, dsn=4.3.2, status=deferred (host 127.0.0.1[127.0.0.1] said: 421 4.3.2 Service shutting down, closing channel (in reply to RCPT TO command))
2025-12-13T04:08:21.838480+00:00 mail amavis[2889]: starting. /usr/sbin/amavisd at mail.mailwhiz.co.uk amavis-2.13.0 (20230106), Unicode aware, LANG="C.UTF-8"
2025-12-13T04:08:21.838556+00:00 mail amavis[2889]: perl=5.038002, user=987, EUID: 987 (987); group=(), EGID: 987 987 (987 987)
2025-12-13T04:08:21.943510+00:00 mail amavis[2889]: Net::Server: Group Not Defined. Defaulting to EGID '987 987'
2025-12-13T04:08:21.943577+00:00 mail amavis[2889]: Net::Server: User Not Defined. Defaulting to EUID '987'
2025-12-13T04:08:21.948279+00:00 mail amavis[2889]: No ext program for .F, tried: unfreeze, freeze -d, melt, fcat
2025-12-13T04:08:21.948605+00:00 mail amavis[2889]: No ext program for .zoo, tried: zoo, unzoo
2025-12-13T04:08:21.948783+00:00 mail amavis[2889]: No decoder for .F
2025-12-13T04:08:21.948811+00:00 mail amavis[2889]: No decoder for .zoo
2025-12-13T04:08:21.948828+00:00 mail amavis[2889]: Using primary internal av scanner code for clamav-socket
2025-12-13T04:08:30.326083+00:00 mail amavis[2926]: starting. /usr/sbin/amavisd at mail.mailwhiz.co.uk amavis-2.13.0 (20230106), Unicode aware, LANG="C.UTF-8"
2025-12-13T04:08:30.326180+00:00 mail amavis[2926]: perl=5.038002, user=987, EUID: 987 (987); group=(), EGID: 987 987 (987 987)
2025-12-13T04:08:30.419873+00:00 mail amavis[2926]: Net::Server: Group Not Defined. Defaulting to EGID '987 987'
2025-12-13T04:08:30.420046+00:00 mail amavis[2926]: Net::Server: User Not Defined. Defaulting to EUID '987'
2025-12-13T04:08:30.424382+00:00 mail amavis[2926]: No ext program for .F, tried: unfreeze, freeze -d, melt, fcat
2025-12-13T04:08:30.424661+00:00 mail amavis[2926]: No ext program for .zoo, tried: zoo, unzoo
2025-12-13T04:08:30.424829+00:00 mail amavis[2926]: No decoder for .F
2025-12-13T04:08:30.424873+00:00 mail amavis[2926]: No decoder for .zoo
2025-12-13T04:08:30.424890+00:00 mail amavis[2926]: Using primary internal av scanner code for clamav-socket
2025-12-13T04:09:36.083249+00:00 mail postfix/postscreen[3100]: CONNECT from [213.209.157.55]:61503 to [217.154.37.167]:25
2025-12-13T04:09:36.089466+00:00 mail postfix/dnsblog[3101]: addr 213.209.157.55 listed by domain zen.spamhaus.org as 127.0.0.3
2025-12-13T04:09:36.089541+00:00 mail postfix/dnsblog[3101]: addr 213.209.157.55 listed by domain zen.spamhaus.org as 127.0.0.4
2025-12-13T04:09:36.597782+00:00 mail postfix/postscreen[3100]: HANGUP after 0.51 from [213.209.157.55]:61503 in tests before SMTP handshake
2025-12-13T04:09:36.597869+00:00 mail postfix/postscreen[3100]: DISCONNECT [213.209.157.55]:61503
2025-12-13T04:10:11.188373+00:00 mail postfix/anvil[2633]: statistics: max connection rate 1/60s for (smtpd:103.168.172.156) at Dec 13 04:06:50
2025-12-13T04:10:11.188575+00:00 mail postfix/anvil[2633]: statistics: max connection count 1 for (smtpd:103.168.172.156) at Dec 13 04:06:50
2025-12-13T04:10:11.188619+00:00 mail postfix/anvil[2633]: statistics: max cache size 1 at Dec 13 04:06:50
and from sudo journalctl -u amavis -n 50:
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: Stopping amavis.service - Interface between MTA and virus scanner/content filters...
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: amavis.service: Deactivated successfully.
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: Stopped amavis.service - Interface between MTA and virus scanner/content filters.
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: amavis.service: Consumed 1.769s CPU time.
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: Starting amavis.service - Interface between MTA and virus scanner/content filters...
Dec 13 04:08:21 mail.mailwhiz.co.uk systemd[1]: Started amavis.service - Interface between MTA and virus scanner/content filters.
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: starting. /usr/sbin/amavisd at mail.mailwhiz.co.uk amavis-2.13.0 (20230106), Unicode aware, LANG="C.UTF-8"
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: perl=5.038002, user=987, EUID: 987 (987); group=(), EGID: 987 987 (987 987)
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: Net::Server: Group Not Defined. Defaulting to EGID '987 987'
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: Net::Server: User Not Defined. Defaulting to EUID '987'
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: No ext program for .F, tried: unfreeze, freeze -d, melt, fcat
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: No ext program for .zoo, tried: zoo, unzoo
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: No decoder for .F
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: No decoder for .zoo
Dec 13 04:08:21 mail.mailwhiz.co.uk amavis[2889]: Using primary internal av scanner code for clamav-socket
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: Stopping amavis.service - Interface between MTA and virus scanner/content filters...
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: amavis.service: Deactivated successfully.
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: Stopped amavis.service - Interface between MTA and virus scanner/content filters.
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: amavis.service: Consumed 1.546s CPU time.
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: Starting amavis.service - Interface between MTA and virus scanner/content filters...
Dec 13 04:08:29 mail.mailwhiz.co.uk systemd[1]: Started amavis.service - Interface between MTA and virus scanner/content filters.
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: starting. /usr/sbin/amavisd at mail.mailwhiz.co.uk amavis-2.13.0 (20230106), Unicode aware, LANG="C.UTF-8"
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: perl=5.038002, user=987, EUID: 987 (987); group=(), EGID: 987 987 (987 987)
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: Net::Server: Group Not Defined. Defaulting to EGID '987 987'
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: Net::Server: User Not Defined. Defaulting to EUID '987'
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: No ext program for .F, tried: unfreeze, freeze -d, melt, fcat
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: No ext program for .zoo, tried: zoo, unzoo
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: No decoder for .F
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: No decoder for .zoo
Dec 13 04:08:30 mail.mailwhiz.co.uk amavis[2926]: Using primary internal av scanner code for clamav-socket
Dec 13 04:10:19 mail.mailwhiz.co.uk amavis[2942]: (02942-01) (!)connect_to_sql: unable to connect to DSN 'DBI:mysql:database=amavisd;host=127.0.0.1;port=3306': Access denied for user 'amavisd'@'localhost' (using pa>
Dec 13 04:10:19 mail.mailwhiz.co.uk amavis[2942]: (02942-01) (!!)TROUBLE in process_request: connect_to_sql: unable to connect to any dataset at /usr/share/perl5/Amavis/Out/SQL/Connection.pm line 255.
Dec 13 04:10:19 mail.mailwhiz.co.uk amavis[2942]: (02942-01) (!)Requesting process rundown after fatal error