sa-update rules were reverted to an earlier state to avoid this and other possible surprises. Bug #6560 has a patch under review to avoid this problem in the future.
Some kind of bug in the auto-promotion backend has mistakenly made active several of the SpamEatingMonkey (SEM) network rules including the SEM DNSBL and URIBL’s. It is a matter of policy that Spamassassin NEVER adds new network rules in stable updates because it can cause significant unexpected problems to server administrators. Furthermore, SpamTips.org strongly recommends against the use of SEM’s DNSBL due to its extremely high overlap with the high scoring PBL. The Bug #6220 indicates one kind of serious issue that can happen when network rules are mistakenly added to sa-update where they very quickly hit usage limits and the provider causes all queries to become false positive hits. Read more to learn how to workaround this issue.