Postfix - Dovecot SASL problem

[Sahil Tandon]

[ I agree with Jerry that this question belongs on postfix-users,
  but I hope my response is helpful ]

On Thu, 2011-08-18 at 23:38:58 +0200, Petr Holub wrote:

> I'm using mail/postfix with WITH_DOVECOT2=yes and mail/dovecot2 with MySQL
> backend for users from FreeBSD ports:
> dovecot-2.0.12
> postfix-2.8.4,1
> 
> I'm unable to get SMTP authentication working using Dovecot SASL with
> ----
> postfix/main.cf:

Generally, when asking for help with Postfix, it is better to provide
the output of 'postconf -n' rather than snippets of your main.cf.

> ...
> smtpd_sasl_security_options = noanonymous, noplaintext
> smtpd_sasl_tls_security_options = noanonymous

So you prohibit plaintext SASL authentication unless the session is TLS
encrypted.

> When attempting to use Dovecot for SMTP SASL auth, what I get is 
> ----
> 2011-08-18 23:31:57auth: Debug: Loading modules from directory: /usr/local/lib/dovecot/auth
> Aug 18 23:31:57 mail postfix/smtpd[57411]: fatal: no SASL authentication mechanisms

There are no TLS connection lines in your log excerpt; if we assume that
no encrypted session was established, then this error makes sense if ...

>         MECH    PLAIN   plaintext
>         MECH    LOGIN   plaintext

dovecot only offers plaintext authentication mechanisms, which you have
configured Postfix to explicitly disallow for non-TLS sessions.

-- 
Sahil Tandon <sahil at FreeBSD.org>