[Dovecot] best choice of user database file to work with postfix

[Stan Hoeppner]

Phil Howard put forth on 4/22/2010 3:07 PM:

> I would think the general (insert some character here)-separated file should
> be doable:
>     comma-delimited:/some/file/name
>     colon-delimited:/some/file/name
>     tab-delimited:/some/file/name
>     space-delimited:/some/file/name
> But it hasn't been done that I can see (some third party patch not
> withstanding).

It's not exactly what you're asking for here, but it sounds like SQLite
would fit your needs.  If only both Postfix and Dovecot had an SQLite driver
for user and pwd lookup.  At this time I believe neither does.

> well be the description given early to use Dovecot SASL to authenticate
> Postfix submission users would be just fine, as long as Postfix does a SOFT

This is a very populate way to integrate the two, and works well.

> rejection when Dovecot isn't up, so it requeues files.  On the SMTP end, I
> just want an up front rejection decision to avoid backscatter.  The one
> backscatter hole where an existing user is being deleted while incoming mail
> is being queued is probably insignificant.

Postfix is very configurable in this regard and is smart enough to return a
4xx when it can't talk to Dovecot (or any "remote" auth provider) and a 5xx
when Dovecot says unknown user.  I'm not looking at docs now, but upon a
brief scan earlier I recall at least 3 different rejection codes Postfix
will return depending on the reason an auth attempt fails.  Some of these
are configurable.  One nice thing about Postfix is that the documentation is
_very_ thorough, even if sometimes hard to digest.

Good luck, and please keep us up to date.  This is an interesting topic and
the solution may be useful to others.

-- 
Stan