[Dovecot] Struggle with Postfix/Dovecot-auth and SASL

[Ingo Reimann]

Hi List,

I just updated an old sendmail installation to a modern postfix/dovecot system with mysql backend. Everything works fine but SMTP-AUTH fails with some clients.

The problem is, that with PLAIN (old) clients send the base64 coded form: USERNAME\0USERNAME\0PASSWORD which, as i understand dovecot interprets as MASTERUSER\0USERNAME\PASSWORD. New clients send \0USERNAME\0PASSWORD which works fine. I don`t like to use masterusers, because then everyone would be able to log in as someone else. 

When i don`t have a passdb with master=yes in my dovecot.conf, Dovecot complains
auth(default): passdb(XXXX at YYY.TLD,master): Attempted master login with no master passdbs

If i create a passdb with contains everyone, everyone may look into other mailboxes. No good idea.

I can`t change the old clients, but for now, i don`t know, what i am doing wrong or how to correct it. No real HowTo for my setup on the net, it seems that everyone uses cyrus-sasl.

May anybody help, because i don`t like to switch my setup or use 2 auth daemons.

My System:
Debian Etch, postfix (2.3.7-3), dovecot (1.0.rc15-2)

Best wishes,

Ingo Reimann
System Manager 

--------------------------------------------------------------------
ICSmedia GmbH
in Münster: Soester Straße 13, 48155 Münster
in Dortmund: Mönchenwordt 5, 44137 Dortmund
im Internet: http://www.icsmedia.de

Telefon: (0251) 60 60-403
Telefax: (0251) 60 60-190
E-Mail: ingo.reimann at icsmedia.de
--------------------------------------------------------------------
Geschäftsführung: Frank Wulf
Sitz der Gesellschaft: Münster
Amtsgericht: Münster
HRB: 46 97