UPDATE 3/21/2011: sa-update has disabled these problematic rules.

It seems some mail is triggering a rare bug in re2c (perl) that can cause spamassassin to get stuck in a 100% loop and cause significant problems for a server.  While this is a very serious problem, it affects only non-default configurations that use sa-compile.  Upstream is working on an emergency sa-update rule push to force disable.  Until then you can workaround this problem in two possible ways below.

Stop Using sa-compile

  1. Turn off whatever runs sa-compile.
  2. Delete /var/lib/spamassassin/<VERSION>
  3. sa-update
  4. Restart your spamd.

Continue using sa-compile, but Manually Disable some Rules

  1. Add these three lines to your local.cf.
  2. sa-compile how you normally would do.
  3. Restart your spamd.

(I personally don’t use sa-compile because this is not the first time it caused weird bugs, and its time savings seems to be insignificant compared to the delay of waiting for network queries.)