Steve Dondley via dovecot skrev den 2024-01-22 02:18:
I have a mail server using dovecot that has been running without issue for quite a couple of years now. It serves email for about 30 individuals.
But since Jan 14th, users have been reporting spurious errors in MS Outlook:
324 Jan 21 00:38:17 ip-172-30-0-131 dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=118.xxx.xxx.xxx, lip=172.30.0.131, TLS handshaking: read(size=596) failed: Connection reset by peer, session=
there is no user in the above line
Some characteristics of the problem that may offer a clue:
- happening with multiple users, not just the same one
- happens from different IP addresses.
bots detected
- happens about 3 to 5 times per day and the errors come in batches like above
- MS Outlook error is:
why is it a microsoft problem now ?
reported error (0x80042109): ‘Outlook cannot conect to your outgoing SMTP email server. If you continue to receive this message….blah blah blah
disable pop3 in dovecot, problem is then gone
I googled the error code but didn’t find anything particularly helpful.
we all use minimal tls1.2, the bots still use ssl, with username fails
I’m running Debian bullseye, version 11.8.
irelevant info