Lately, a bunch of my cctalk messages got into my spam
folder.
That never used to happen, and I didn't make any changes locally.
Every so often that happens to me with Yahoo as the relay; they change their
spam filters slightly and it starts trapping a few classiccmp messages
(although not nearly all). I end up having to go in via the web interface,
receive a single classiccmp message and flag it as 'not spam' - then it'll
work fine again for all classiccmp messages for a few more months before the
cycle repeats.
So, possibly a 'problem' with your ISP / mail provider?
cheers
Jules