>> 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