Re: [exim] Strange log entry about backup MX

Heiko Schlittermann, 2010-06-16 11:36:

> But it's quite stupid by second mx, to think that my (network)
> connectivity to the second mx is the same as to the first mx.

This highly depends on the setup.
I have only a single (private) mail server which has two IP addresses,
so the connectivity, availability and everything of both MXs is just the
same.

Many spammers just send their crap to the lowest priority MX, so
blocking stuff on the second MX that didn't try the first MX before is
an easy anti-spam measure.

btw, I also use this the other way round: Hosts that get greylisted (on
the first MX) are immediately accepted on the second MX. This way,
messages from the few hosts that get greylisted (which I only do
sparsely) are delayed as little as possible. Most MTAs are decent enough
to get through, the most prominent and notorious exception is qmail.