Issue Email Sending After installing Update No. 2 not working (Obsidian 18.0.29)

[WhizzHacks]

Hello,

I installed update number 2 from plesk obsidian 18.0.29 today. Unfortunately my mail server has stopped working and I cannot find any problems. It worked without any problems before.

ERROR:

SMTP Error: data not accepted.SMTP server error: DATA END command failed Detail: Service unavailable - try again later\r\n SMTP code: 451 Additional SMTP info: 4.7.1

mail.err:

Aug 24 21:06:38 psa-pc-remote[7269]: _mh_fork(): The child process with pid 28942 killed by signal 11
Aug 24 21:06:38 psa-pc-remote[7269]: Error during 'dd51-domainkeys' handler

maillog:

Aug 25 09:19:13 postfix/cleanup[20771]: 940512004E: milter-reject: END-OF-MESSAGE from x[x.x.x.x]: 4.7.1 Service unavailable - try again later; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<x>
Aug 25 09:19:13 postfix/smtpd[20764]: disconnect from x[x.x.x.x] ehlo=2 starttls=1 auth=1 mail=1 rcpt=1 data=0/1 quit=1 commands=7/8

It's not a configuration error, I've tried fixing all of them but can't figure out what the exact error is.

 

[WhizzHacks]

Now after downgrading from plesk to the old version and importing my backup, it works fine again, but when I update plesk, which I want to do, it stops working. Doesn't anyone have the same problem as me?