550 smtp auth required - for incoming mail

Community Support Mail
1

hi,

one of our domains can’t receive emails from our Zimbra email server. The answer is 550 smtp auth required, which is odd. Why would an incoming email trigger an SMTP error? Have you seen such before? What should I check?

This is what I see from the sending part:
Jul 24 08:44:54 mail postfix/smtp[30974]: 3A0CAA14C6: to=[email protected], relay=127.0.0.1[127.0.0.1]:10032, delay=0.33, delays=0.09/0.01/0/0.22, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 875169F76D)
Jul 24 08:44:54 mail postfix/smtp[30975]: 875169F76D: to=[email protected], relay=mail.vetop.hu[185.80.50.84]:25, delay=0.19, delays=0/0.01/0.14/0.04, dsn=5.0.0, status=bounced (host mail.vetop.hu[185.80.50.84] said: 550 smtp auth required (in reply to RCPT TO command))

2

Hi @Jess,

The important log is the one on your server.

exigrep '<= [email protected]' /var/log/exim4/mainlog*
3

Hi @sahsanu ,

well, that is strange… it starts from 9:31 today, however the mail was sent at 8:44 and no sign of it:

still don’t really understand what that Unroutable address is (it is an account on our other server).

4

If you can’t see anything in the log, maybe that mail didn’t reach your mail server…

Note: next time, please, copy and paste the output, is a pain to read logs in screenshots :wink:

Do you resolve different.hu (A record and MX record) from your Hestia server?
Can you connect to the different.hu MX server from your Hestia server?

5

Sure sorry… :slight_smile:

But in the initial log lines, 185.80.50.84 replies with 550 - which is the Hestia server.

Both different.hu and mail.different.hu is resolving:

root@hestia:/var/log/exim4# ping different.hu
PING different.hu (185.43.206.92) 56(84) bytes of data.
64 bytes from cyber.different.hu (185.43.206.92): icmp_seq=1 ttl=63 time=1.43 ms
64 bytes from cyber.different.hu (185.43.206.92): icmp_seq=2 ttl=63 time=0.649 ms

root@hestia:/var/log/exim4# ping mail.different.hu
PING mail.different.hu (193.39.15.116) 56(84) bytes of data.
64 bytes from mail.different.hu (193.39.15.116): icmp_seq=1 ttl=63 time=0.893 ms
64 bytes from mail.different.hu (193.39.15.116): icmp_seq=2 ttl=63 time=0.458 ms

There are a few websites on Hestia which are using mail.different.hu as SMTP and that seems to work. :confused:

6

Then Exim should have some lines about it in the logs… Check /var/log/exim4/rejectlog instead of `

Check if you can connect to port 25:

telnet mail.different.hu 25