All the Y2K issues were after all quite a let down yielding almost no exciting failures or blue screens of death.

I did however come across a minor bug in Zimbra and Spam Assassin today which was slightly confusing and an example of some pretty bad programming. Spam Assassin has a number of rules which determine whether an email is valid or not; one such rule is whether an email is dates "grossly in the future".

We noticed that more emails where being detected as spam more than usual. In further investigation this code was found in 72_active.cf :

##{ FH_DATE_PAST_20XX
header FH_DATE_PAST_20XX Date =~ /20[1-9][0-9]/ [if-unset: 2006]^M
describe FH_DATE_PAST_20XX The date is grossly in the future.^M
##} FH_DATE_PAST_20XX

This generates FH_DATE_PAST_20XX on almost all emails. Clearly the programmer could see that when the date goes from 2009 to 2010 this would be illegal.

Anyway, the problem is easily solved:

##{ FH_DATE_PAST_20XX
header FH_DATE_PAST_20XX Date =~ /20[2-9][0-9]/ [if-unset: 2006]^M
describe FH_DATE_PAST_20XX The date is grossly in the future.^M
##} FH_DATE_PAST_20XX

And thankfully happy customers again :)

Note: It also seems like someone else found this too