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

[Phil Howard]

On Thu, Apr 22, 2010 at 5:42 AM, Thomas Leuxner <tlx at leuxner.net> wrote:

> On Thu, Apr 22, 2010 at 11:18:09AM +0200, Rainer Frey wrote:
> > What I don't see here at all (and neither in your Wiki Howto) is how
> Postfix
> > determines the valid recipients for the domains in
> virtual_mailbox_domains.
>
> Postfix will expand possible aliases first and determine the final
> recipient handing over to Dovecot:
>
> virtual_alias_maps = hash:/etc/postfix/virtual
>
> It will query the recipients by connecting to the socket in its
> chroot provided by Dovecot:
>
> service auth {
>  unix_listener /var/spool/postfix/private/auth {
>    group = postfix
>    mode = 0660
>    user = postfix
>  }
>  user = doveauth
> }
>
> Once it has the homedir it will send it off via LMTP or deliver,
> whichever you configured via:
>
> virtual_transport = lmtp:unix:private/dovecot-lmtp
> or
>
> virtual_transport = dovecot
>
> >
> > The correct parameter would be  virtual_mailbox_maps, but AFAIK there is
> no
> > lookup table that read the passwd format from an arbitrary file. So a
> script
> > that generates a hash/whatever postfix lookup file from the passwd-files
> would
> > still be necessary.
>
> There is no such thing as a correct parameter from my perspective. I did
> not say that alias creation was to be unified/automated. Instead I said I
> did not even think
> this is good practice to me. Anyone with at least a bit of sed/awk
> knowledge
> can kludge it from the flat-files anyway.
>

So your suggestion for local_recipient_maps is to read from a table
extracted from the file used by Dovecot.  And then use the previously
described setup (now in the Wiki) for a proper submission interface (using
SASL and asking Dovecot).'

I have Dovecot 1.1.11, and for now using package versions outside of what
Ubuntu offers isn't an option (that's something I'll be doing later with a
different distribution, but it isn't an option right now).  So I can't have
submission ask via LMTP.  If I can get Postfix to authenticate via passwords
in a btree or cdb, I guess I can just copy BOTH usernames AND passwords from
the file Dovecot reads from and build the btree or cdb db file for Postfix
from there.

Any chance Dovecot can read either btree or cdb files directly?