Hello all,
I have two mailservers, a primary and a secondary MX.
The primary MX is a spamassassin (3.2.3 on Ubuntu Linux) box that is
placed inline of a MS Exchange machine.
Spamassassin is doing a good job, especialy with the RBL's I am using.
The backup MX is a simple EXIM which does only forwarding (to the
spamassassin box) without any spam control.
This setup should be simple yet effective, if the Pri MX dies, the
forwarder will hold all the mail and wait until the SA box is back up
and then send the queued mail to it. It will then be filtered again,
that way I dont have to sync whitelists, greylist databases and all my
rules to the second MX.
The problem now lies with the RBL's, when the SA box dies, the mail will
be queued on my Exim box and when service is restored, it will forward
it again BUT the last "Received from:" path will be of course the Exim
host IP. SA will then do a lookup on the wrong IP. Basically I want my
Exim box (second mx) to be invisible or need the headers to be rewritten
so Spamassassin does a correct lookup on the IP BEFORE it got to the SA.
I've heard about SRS, I don't know precisely if that will do the trick
for me, anyone has some more information, tips or tricks? It's rather
complex matter and I can't find any good documentation on how to solve
this problem.
Kind regards,
Rense
