Re[2]: False Primary MX Record = MORE spam?

[Peter Nitschke <em...@ace.net.au>]

>> I found A LOT of spam tries secondary MX first as a way to circumvent
>> spam filters..
>
>I don't think there's anything that prohibits you from listing a server 
>multiple times, so you could include your primary in multiple MX records, 
>including 1st, 2nd, and last.


Here are some figures for the last 18 hours.
3 mail server gateways
4 MX listings

MX10 = mail1 (listed twice)
MX20 = mail2
MX30 = mail1 (listed twice)
MX40 = mail3

Rejected:
mail1 = 6624
mail2 = 3006
mail3 = 2986

Spam:
mail1 = 163
mail2 = 10
mail3 = 7

Accepted:
mail1 = 2780
mail2 = 78
mail3 = 77

Depending how you look at it, the number of rejects could be roughly even
for all MX (if you count mail1 twice as it has 2 MX listings - approx 3000
rejects for each MX.  Either way, it's not showing more spam being
targetted at the 2nd or 4th MX.

However I am aware that this is only over 18 hours, it might change with a
longer time sample.

Peter