Using procmail to remove backdated spam

Question

I started getting spam backdated by a few years. Is there an easy way to detect and divert these to /dev/null using procmail?

Answer 1

If the date is definitely present then something simple like:

 # The order of the recipes is significant
 #  header format is "Date: Sat, 13 Feb 2010"
 :0
 * ^Date: .*,.*200[0-9]
 /dev/null

Answer 2

It's actually independent of procmail, but a cronjob that run at a fixed period could do this:

find /maildirectory -type f -mtime +7 -exec rm -rf {}\;

This would delete mail over a week old.