Rob McEwen (PowerView Systems) wrote:
Jon Trulson said:
Hehe, that is an old spammer trick... Our secondary MX is
pretty much 100% spam.
I implemented greylisting on the secondary which reduced spam
through it by about 99% :) The secondary does not do spam
scanning, it's simply store and forward. Greylisting really
helps in these cases.
Jon, please tell me, what portion of your overall spams attempt to comes in
through this secondary MX compared to all spam that you catch which are headed
to your primary MX record.
Here are some rough numbers from my systems:
Yesterday on the secondary MX:
Connections: 24601
Blocked for RBL: 22841
Roughly similar time period on primary MX:
Connections: 176668
Blocked for RBL: 79994
Delivered: 17168
