I have a DV server over at MediaTemple, and recently I started to get a lot of legitimate mail marked as spam. I checked out the raw headers in the email, and they all had FH_DATE_PAST_20XX in the X-Spam-Status header.

Turns out SpamAssassin had a bug with that particular rule, which would make it think 2010 dates were “grossly in the future”. Running sa-update should solve it.

More info at http://kb.mediatemple.net/questions/1792/SpamAssassin+2010+bug