rblfilteris a simple tool which can be used to identify mail from RBL-listed sources. You configure it with a list of hosts on which you receive mail, and it extracts the sender's IP address from the "
Received:" headers. It is useful when you have no control over the SMTP listener which receives your mail - e.g. at your ISP.
Once configured, it is quite smart about matching the correct
Received: header, and it can parse the formats produced by most
common mailers. The current implementation is in perl.
You do get a number of false positives by filtering against RBLs, but if you include an exception for messages which are addressed to you personally, you get a very effective yet simple spam filter:
# Keep mail if I am listed as recipient in the headers :0: * ^TO(brian|btc|b\.candler) $DEFAULT # Filter RBL-listed sources :0: * ! ?/u/home/brian/bin/rblfilter Mail/junk
Find out more by reading the man page.