[Dovecot] What best decision to make for flatfiles or SQL when I use Dovecot2 + Postfix together?

[Rainer Frey]

On 28.09.2011, at 00:14, terryjames9461 at mm.st wrote:

> Hello Patrick,
> 
> On Tuesday, September 27, 2011 6:06 PM, "Patrick Domack"
> <patrickdk at patrickdk.com> wrote:
>> Using dovecot lda/lmtp you remove all postfix needs to know mailbox  
>> name to directory mapping, that would be duplicated.
> 
> With using the Dovecot lmtp option, where does Postfix know to refuse
> email for a non-existing user or domain?  That also has to be shared?

I wondered that as well, and unfortunately the Howto doesn't explain 
the concept it builds upon. But I found it: it uses LMTP and recipient verification 
(see reject_unverified_recipient in smtpd_recipient_restictions).

See http://www.postfix.org/ADDRESS_VERIFICATION_README.html for details.

Rainer