> On Jan 25, 2018, at 8:51 PM, Anvar Kuchkartaev <an...@anvartay.com> wrote:
>
> For dns optimizations I recommend to put other domain1 MX hosts IP addresses
> to the /etc/hosts file and disable postfix dns lookups so you will reduce
> volume of dns lookups dramatically.
This is not good advice, it breaks delivery to other domains. Much better
to run a local caching resolver. Note also that the OP reports that raising
concurrency does not improve throughput by much. If DNS lookups were slow
higher concurrency would lead to a significant throughput increase.
> And defining static transport entry also reduces MX lookups.
If there are no MX records, and the destination is served by a single host,
one can indeed gain modest efficiency by putting in a transport entry with
the nexthop in [].
> Second you must use connection caching in Postfix to reduce performance
> overhead.
Postfix will by default cache non-TLS connections on demand (when there's
a backlog, which presumably applies to the OP's traffic). If the
destination is using TLS, then connection caching is not an option. We
don't yet a connection cache for TLS>
> Both optimizations possible in Postfix 2.10. But not earlier versions.
This is not the case. Connection caching dates back to around Postfix
2.2, and bypassing DNS lookups has been around even longer and still
not a good idea except in very special cases.
--
Viktor.
