Browsing the log files on my MIAB server, I saw rejected replies from opensuse.org, and looked into it.
The box has sent a few mails like these:
Feb 8 17:32:30 mail postfix/pickup: 039268712C: uid=120 from=<opendmarc> Feb 8 17:32:30 mail postfix/cleanup: 039268712C: message-id=<20220208163230.039268712C@mail.server> Feb 8 17:32:30 mail postfix/qmgr: 039268712C: from=<firstname.lastname@example.org>, size=9381, nrcpt=1 (queue active) Feb 8 17:32:34 mail postfix/smtp: 039268712C: to=<email@example.com>, relay=mx2.opensuse.org[188.8.131.52]:25, delay=4.3, delays=0.08/0.03/0.52/3.7, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as B9A746480) Feb 8 17:32:34 mail postfix/qmgr: 039268712C: removed
There’s a reply too which is being rejected:
Feb 9 18:10:53 mail postfix/smtpd: NOQUEUE: reject: RCPT from proxy-nue1.opensuse.org[184.108.40.206]: 550 5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in virtual mailbox table; from=<email@example.com> to=<firstname.lastname@example.org> proto=ESMTP helo=<anna.opensuse.org>
What’s going on here?