Issue Plesk 18.0.73 - postfix/smtpd fatal: no SASL authentication mechanisms

[LRLD]

Server operating system version

Ubuntu 24.04.3 LTS

Plesk version and microupdate number

Plesk Obsidian 18.0.73 Web Pro Edition

Morning,

I was just sending a test mail on my systems to make sure everything was ok after the Dovecot update, only to find my mail being held in the queue.
I see lots of...mail postfix/smtpd[3261]: fatal: no SASL authentication mechanisms in the mail.err log since the update to 18.0.73 yesterday.
Looking at the /etc/postfix/sasl/smtpd.conf file, showed just PLAIN LOGIN so I had to add back in DIGEST-MD5 CRAM-MD5 so the file looked like this again...

pwcheck_method: auxprop saslauthd
auxprop_plugin: plesk
saslauthd_path: /private/plesk_saslauthd
mech_list: DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
sql_engine: intentionally disabled
log_level: 4

I hope this helps the next person.
Regards

LD

 

[Linulex]

Thank you LD,

that helped an is the solution, but on almalinux ( and other redhat derived systems ) the smtpd.conf is in

/etc/sasl2/smtpd.conf

I had the same problem, port 465 refused an encrypted password saying the server doesn't support that.

The fix is the same

Regards
Jan

 

[Martin.B]

Is it safe to put back in the MD5-Mechanisms?
We have users with Thunderbird having problems after the update. However I remember the mechanisms were removed in the past, because of problems with outlook. (https://support.plesk.com/hc/en-us/...-authentication-failed-authentication-failure)
Would be kinda pointless, if we repair the smtp for thunderbird users and in exchange get problems with the outlook users.

 

[Linulex]

The problems you are referring to are for dovecot, this is a fix for postfix.

postfix = smtpd
dovecot = imap and pop3

regards
Jan

 

[Martin.B]

Ah, I had the wrong link:

https://support.plesk.com/hc/en-us/articles/12377868137879-Outlook-fails-to-send-an-email-SASL-authentication-failure-On-Plesk-for-Linux

 

[LRLD]

Ah, I had the wrong link:

https://support.plesk.com/hc/en-us/articles/12377868137879-Outlook-fails-to-send-an-email-SASL-authentication-failure-On-Plesk-for-Linux

If you've had issues with DIGEST-MD5 I would leave it out, as suggested in the link...

/etc/postfix/sasl/smtpd.conf

pwcheck_method: auxprop saslauthd
auxprop_plugin: plesk
saslauthd_path: /private/plesk_saslauthd
mech_list: CRAM-MD5 PLAIN LOGIN
sql_engine: intentionally disabled
log_level: 4