It seems that every year at the start of the year there is some computer related issue. This time the bug has struck Spamassassin a tool used by many web host in Spam Filtering. The bug seems to affect both Spamassassin versions 2.x and 3.x.
The bug lies in a rule, FH_DATE_PAST_20XX, that checks for email with forward dates e.g. 2010,2011... 2020. However the rule worked fine for mail with dates 2000-2009 but we are now in 2010.
Solution: (Quick Fix)
There are a few approaches
1. Add local.cf
Add this rule
score FH_DATE_PAST_20XX 0
2. 50_scores.cf
Find 50_scores.cf and edit it
change
score FH_DATE_PAST_20XX 2.00753.384 3.554 3.188 #n=2
to
score FH_DATE_PAST_20XX 0 #n=2
You might need to restart you spamd process .
Note: this is a quick fix not a permanent solution
a) if your spamassassin settings are global and not on a user by user basis. You will need to update the user settings.
b) The rule needs correcting
A bug report has been filed by users.
References