Karl sent us a note about date parsing issues in Spamassassin.  I thought we fixed all of these problems ten years ago when we went through the Y2K transition.  Apparently not.  More details are at these URLs:

http://www.arrfab.net/blog/?p=174
https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6269
http://svn.apache.org/viewvc/spamassassin/trunk/rulesrc/sandbox/emailed/00_FVGT_File001.cf?r1=794319&r2=796216&diff_format=h

Thanks for the info Karl!

UPDATE 1

In addition to the comments below, one of our readers sent in this note:

Run "saupdate" or create the following line in your local.cf file:

score FH_DATE_PAST_20XX 0

You can learn about sa-update here:

http://wiki.apache.org/spamassassin/RuleUpdates

The sa-update path is preferred.

Thanks for the comments Joanne!

Marcus H. Sachs
Director, SANS Internet Storm Center