Matus UHLAR - fantomas:
> >smtp_connection_cache_destinations enables connection caching
> >*unconditionally* for the named destinations. This means it keeps
> >a connection open for several seconds even when the destination has
> >no email in the active queue.
> >
> >I think that you can stick with the default settings, which
> >keep connections open only when they can be reused immediately.
>
> this unfortunately did not work without listing destinations explicitly in
> smtp_connection_cache_destinations so I had big backlog of messages for
> those domains, even if I set smtp_connection_cache_time_limit=30 and
> enabled smtp_tls_connection_reuse...
I suspect that you have a different problem: using the same Postfix
delivery agents (default_transport = smtp) for forwarding internal
domains, and for external deliveries.
Instead, mail for the internal domains should be delivered with
"relay_transport = relay" (or some other transport that is different
from $default_transport), so that a small number of internal domains
is not competing for resources against a large number of external
domains.
For example:
/etc/postfix/main.cf:
default_transport = smtp
transport_maps = hash:/etc/postfix/transport
/etc/postfix/transport:
example.com relay:[inside.example.com]
sales.example.com relay:[mail.sales.example.com]
eng.example.com relay:[eng.example.com]
Looking at http://www.postfix.org/STANDARD_CONFIGURATION_README.html#firewall
I see that the firewall/gateway example hasn't been updated after
the relay transport was introduced.
Wietse
