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

[Phil Howard]

On Wed, Apr 21, 2010 at 1:30 PM, Rodolfo Gonzalez <rgonzalez at gnt.cc> wrote:

> Phil Howard escribió:
>
>  On Wed, Apr 21, 2010 at 10:47 AM, Patrick Nagel <mail at patrick-nagel.net
>> >wrote:
>>
>>  I think /etc/passwd is as close as it gets to your requirements... why
>>> not
>>> just add the users as system users, and set their shell to /bin/false?
>>>
>>>
>> There would be conflicts in this, especially with multiple domain names
>> (sorry, forgot to mention that ... there will be about 10 domain names).
>>
>
>
> Then I think MySQL will do the job. Both postfix and dovecot support MySQL,
> and you can use SASL to authenticate SMTP with Dovecot, so Dovecot would do
> all the auth work. Finally, you could use Postfix's VDA patch if you want to
> use Maildir++.
>
> Hope this helps.
>

I don't want to use any other server engine of any kind with this.  I'm
trying to keep it small and lean, and minimize what the people that have to
monitor and fix it need to know.  So at the present time, I am excluding all
databases like any SQL or LDAP or anything else that needs to run as a
daemon/engine/service.

Ideal would be a single file both can read, be it a flat file, or a Berkeley
DB file.  Next to that would be two files where one is authoritative and the
other (for Postfix since it only needs a list) is generated from it.  That
looks like what I ultimately will do (the script that adds users will just
generate the files and test them).

I was hoping there might be a way to get Postfix to use the legacy Unix
passwd file format, but with a different file name.  It doesn't seem to have
that ability.  It would make things very simple if it did.  It would also be
simple if the system /etc/passwd file could be used, but it can't.