Issue Client mail randomly asks for password

[Kniar]

Hello,

Since about 2 weeks, my customers report me that their Outlook randomly asks for mail password. If they type it, it doesn't work and asks it again and again. And few minutes later it works normally without any change server-side or client-side.

Note that if I run the command "plesk repair mail domain.com" the problem disappears immediatly. But it'll occur again later.

In maillog I see :
postfix/smtpd[30747]: warning: unknown[xxx.xxx.xxx.xxx]: SASL DIGEST-MD5 authentication failed: authentication failure

My conf : Plesk 12.5.30 on CentOS 6 / Fail2ban enable for plesk-courierimap and plesk-postfix.

Thanks for your help.

 

[IgorG]

Try to use this solution Outlook fails to send an email: SASL authentication failure

 

[Kniar]

Thanks for your answer. I saw in other post that some people that delete DIGEST-MD5 had then another issue. Hope this will not be the same for me.

That I do not understand is why the problem appears randomly for customers. The server was working fine for years.

 

[IgorG]

That I do not understand is why the problem appears randomly for customers. The server was working fine for years.

Maybe the problem on MS side? Do you have the same problem with another mail clients?

 

[Kniar]

It seems that problem occurs only with Outlook customers but not totally sure at this point. We have another Plesk server in exactly same configuration (12.5.30 on CentOS 6 with a lot of customers too) that does not have problem at all. I compared /usr/lib64/sasl2/smtpd.conf and some other files. Exactly the same (not any more now since à remove DIGEST-MD5 from first one).