All mail marked as spam?

[Michael Chase]

Hi,

I have a mailscanner/mailwatch/postfix/spamassassin/clamav setup that's
been serving me well for several years (with the occasional update).

In the last 24h or so, it's been marking all mail, even messages with a
score of 0.0, as possible spam.

I have anything >3.0 flagged as possible spam, quarantined and emailed
to postmaster. Anything >6.0 is spam and just quarantine.

Looking at the messages in mailwatch, the 0.0 score ones don't have any
info on why spam assassin thought they were bad, presumably because it
didn't (score = 0.0). Real spam has details on the breakdown of the score.

There does not seem to me any errors when MailScanner is restarted.

Where should I start to look for the problem? I've not changed anything
for weeks/months, so I'm puzzled that it has started to act strangely.

Michael.