SASL authentication failure

[Erwan]

Hello,

Since 3 weeks, some customers can't retrieve their messages (Outlook / POP3) for one or two hours (
the window asking the user name and password is displayed)... and and then everything returns to normal use.
All is ok with server (Plesk 12.5 / Postfix). The only thing we see in the maillog file is :

Mar 2 13:36:06 servXX postfix/smtpd[9690]: connect from unknown[x.x.x.x]
Mar 2 13:36:06 servXX postfix/smtpd[9690]: warning: SASL authentication failure: realm changed: authentication aborted
Mar 2 13:36:06 servXX postfix/smtpd[9690]: warning: unknown[x.x.x.x]: SASL DIGEST-MD5 authentication failed: authentication failure

I do not see where the problem is and why it is happening now (since Plesk update ?).

Thank you for your help.

 

[Sean P]

I'm glad I'm not the only one! I switched to Postfix a week or so ago as all emails sent via Qmail were being blocked by Gmail.

Every other day I get hundreds of complaints from customers that their password prompt keeps popping up in Outlook, I check the logs and get

Mar 2 12:45:15 mail postfix/smtpd[859]: warning: SASL authentication failure: realm changed: authentication aborted
Mar 2 12:45:15 mail postfix/smtpd[859]: warning: unknown[41.58.154.197]: SASL DIGEST-MD5 authentication failed: authentication failure

If I restart postfix it normally fixes it for a while but not before I end up with an inbox full of complaints!

I've got over 3000 live email accounts on this server and this is getting ridiculous and is costing us time and money!

 

[Erwan]

Hello,

I've made that:
Backup the file smtpd.conf, and replace there a string <mech_list: DIGEST-MD5 CRAM-MD5 PLAIN LOGIN> to <mech_list: CRAM-MD5 PLAIN LOGIN>.

I wait to see if that solves the problem....

 

[Sean P]

I did try that but unfortunately it never resolved the problem.