A little analysis of the X-Spam-Status: headers showed that all of the misfiled messages (and lots of messages that didn't quite make it over the threshold) were hitting a rule called DNS_FROM_SECURITYSAGE.
It turned out that this rule is obsolete and has been removed from Spam Assassin, but it hasn't yet been removed from Debian, at least not from Etch.
So I filed a Debian bug. Or at least I think I did -- I got an email acknowledgement from email@example.com but it didn't include a bug number and Debian's HyperEstraier based search engine linked off the bug page doesn't find it (I used reportbug).
Anyway, if you're getting lots of SECURITYSAGE false hits, edit
/usr/share/spamassassin/20_dnsbl_tests.cf and comment out the
lines for DNS_FROM_SECURITYSAGE and, while you're at it, the lines
for RCVD_IN_DSBL, which is also
obsolete. Just to be safe, you might also want to add
score DNS_FROM_SECURITYSAGE 0
in your .spamassassin/user_prefs (or equivalent systemwide file) as well.
Now if only I could figure out why it was setting FORGED_RCVD_HELO and UNPARSEABLE_RELAY on messages from what seems to be perfectly legitimate senders ...
[ 22:54 Nov 12, 2008 More linux | permalink to this entry | ]