nanog mailing list archives

Re: OT? /dev/null 5.1.1 email


From: Todd Vierling <tv () duh org>
Date: Tue, 5 Jul 2005 22:23:13 -0400 (Eastern Daylight Time)


On Tue, 5 Jul 2005, Jim Popovitch wrote:

Generally there's little reason to run a secondary MX. Email will
queue if the sole MX is  offline or unreachable. Email will queue at
senders' mail servers.

The problem with the above is that your (or your users') email delivery
is then dependent upon the configuration and timeouts of someone else's
system (my system drops undeliverables after 1 hour).

True -- however, too many people have so grossly misconfigured secondary MXs
in "traditional" operation mode, in the face of today's blowback bounce spam
world.  Traditional secondary MXs are going the way of open relays, *quick*.

The default recommendation I give anyone these days is to use no
secondaries, and let the sender's mail server queue it up, as that's the
fastest implementation path.  As a second stage, and only if the expertise
and time is available, then a backup MX with some sort of recipient
validation at SMTP time can be implemented.

-- 
-- Todd Vierling <tv () duh org> <tv () pobox com> <todd () vierling name>


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