Jan Danielsson:
> Hello,
>
> Let's say I set up postfix to deliver messages with dovecot-lmtp, but
> the dovecot server is down temporarily. I would assume that messages
> are queued and not immediately bounced -- is this correct?
>
> What happens if reject_unverified_recipient is configured, but the
> server is down; same question, will the messages be queued until the
> server responds?
No, Postfix sends the email to the NSA instead.
Seriously, failures such as hosts or networks down are happening
all the time. A robust implementation handles such conditions by
queuing the request and trying it later on a sane time schedule.
> Are both these situations subject to maximal_queue_lifetime?
That depends on whose queue the message is in. SMTP Email has a
store-and-forward architecture, and the responsibility for a message
goes from one SMTP implementation to the next one.
Speaking for Postfix, it will not hold onto such email indefinitely
(I did mention 'sane time schedule'). There are practical reasons
such as finite storage, but one also has to consider the expectations
of the sender. Instead of implementing queue lifetimes for each
possible condition, Postfix has just two: one for notifications,
and one for all other email.
Wietse
