On Thu, Mar 24, 2011 at 09:41:25AM -0700, Steve Jenkins wrote:
> On Thu, Mar 24, 2011 at 8:28 AM, Victor Duchovni
> <victor.ducho...@morganstanley.com> wrote:
> > A LAN DNS server with a 2ms lookup delay is fine. Unbound, bind, ...
> > does not matter.
>
> Thanks for all the nudges in the right direction. We're now running
> Unbound on the same box as Postfix, getting cached responses in 0 msec
> from the Postfix box, and 1 msec responses from all other boxes in the
> rack. It was as easy as "yum install unbound" and then editing two
> lines in the default config file.
>
> We'll test this week with a big mailing to see if the overall delivery
> times are noticeably improved.
The DNS cache is unlikely to make much difference for outbound mail,
it is much more for incoming mail where you get hammered by zombies.
If all you changed was adding a local DNS cache, unless your previous
cache was >100ms away, you'll not see much change. To get better
treatment from remote systems, get whitelisted by the domains that
represent the largest communities of users.
--
Viktor.
