More anti-spam tuning.

        One thing I've noticed that spammers like to use are invalid date
headers, either way in the future or the past, or just random, to get
into your inbox. One nice thing I've done is setup some regexes in the
headercheck file of Postfix to reject email if it's not within a month
or so of now (stopping all those stupid 2038 emails). I'd like it if I
could automate this, though, so I wouldn't have to periodically update
my filters.
        Between date rejection, greylisting, other sanity checks on the header,
and heavy RBL/SBL settings, I've managed to cut my incoming spam message
count from 1000/week to about 56 a week (which are roughly 99.99% found
by DSPAM, as I get on the order of one false negative every 3 months).
        Ideas?
Received on Sat May 13 02:04:17 2006