Error 554 is deffered instead of bounced

[sysadminfromhell]

Hey there,

so today I noticed that sometimes a SMTP 554 is a DSN=4.0.0 for the Proxmox Mail Gateway and is handling the Mail as 400 errors.
Can I somehow honor the 554 error?

2024-06-26T10:28:48.553610+02:00 mx postfix/lmtp[154285]: 2B8644095D: to=<Somerecipient>, relay=127.0.0.1[127.0.0.1]:10023, delay=1.4, delays=0.02/0.08/0.05/1.2, dsn=2.5.0, status=sent (250 2.5.0 OK (40965667BD13F4AD54))
2024-06-26T10:28:48.553759+02:00 mx postfix/qmgr[973]: 2B8644095D: removed
2024-06-26T10:28:48.834065+02:00 mx postfix/smtp[154291]: 7977E43363: host Somehost[someip] refused to talk to me: 554 Somehost
2024-06-26T10:28:48.859619+02:00 mx postfix/smtp[154291]: 7977E43363: host Somehost[someip] refused to talk to me: 554 Somehost
2024-06-26T10:28:48.912635+02:00 mx postfix/smtp[154291]: 7977E43363: to=<Somerecipient>, relay=Somehost[someip]:25, delay=0.4, delays=0.05/0.08/0.26/0, dsn=4.0.0, status=deferred (host Somehost[someip] refused to talk to me: 554 Somehost)
2024-06-26T10:34:38.742258+02:00 mx postfix/qmgr[973]: 7977E43363: from=<Somesender>, size=1395, nrcpt=1 (queue active)
2024-06-26T10:34:38.854766+02:00 mx postfix/smtp[154361]: 7977E43363: host Somehost[someip] refused to talk to me: 554 Somehost
2024-06-26T10:34:38.883088+02:00 mx postfix/smtp[154361]: 7977E43363: host Somehost[someip] refused to talk to me: 554 Somehost
2024-06-26T10:34:38.926187+02:00 mx postfix/smtp[154361]: 7977E43363: to=<Somerecipient>, relay=Somehost[someip]:25, delay=350, delays=350/0.07/0.1/0, dsn=4.0.0, status=deferred (host Somehost[someip] refused to talk to me: 554 Somehost)

Kind regards,

 

[Stoiko Ivanov]

Could you enable debug logging for the smtp client and show us the logs (if possible without anonymizing things, or at least making sure that different hostnames and different IPs remain consistent) - of such a transaction?
https://www.postfix.org/DEBUG_README.html#verbose