Ubuntu 9.04 affected too, thanks for posting.
Summary: FH_DATE_PAST_20XX matches on yars 2010-2099.
As a workaround until the spamassasin rules are updated, the score can be lowered in local.cf: score FH_DATE_PAST_20XX 0.0
Summary: FH_DATE_PAST_20XX matches on yars 2010-2099.
As a workaround until the spamassasin rules are updated, the score can be lowered in local.cf: score FH_DATE_PAST_20XX 0.0
locate 72_active.cf && sudo vi 'locate 72_active.cf'
search 'FH_DATE_PAST_20XX'
change '/20[1-9][0-9]/' to '/20[2-9][0-9]/'
Source: http://wiki.apache.org/spamassassin/Rules/FH_DATE_PAST_20XX grep FH_DATE_PAST_20XX /var/lib/spamassassin/3.*/updates_spamassassin_org/72_active.cf
If needed, update with this command: sa-update
Then check again to confirm.If you don't already, consider running sa-update daily in a cron job to mitigate the damage from bugs like these and to benefit from other changes.