Does the custom filter function use non-alphabetic characters? I've been trying to filter on spammer addresses located in the message body that begin with an underscore or hyphen. Lots of these starting showing up lately. I screen non-subscriber posts to a LISTSERV list, and the server sends the address to me in the message body. Filtering on _*@*, or -*@*, doesn't catch these addresses.

I was hoping someone would have been able to comment on this by now (not being a mail user myself). The principal resource on "filters not working" is http://forum.spamcop.net/forums/index.php?...amp;#entry12082. You've worked through that? There's a certain amount of discussion elsewhere here about filtering (such as http://forum.spamcop.net/forums/index.php?showtopic=3285 and http://forum.spamcop.net/forums/index.php?showtopic=8753 but none of it is specific to your query or indicates either way about non-alpha characters. Other sources, such as http://worria.com/en/imp-filter.shtml seem to indicate non-alphas are OK, http://wiki.horde.org/FAQ/User/IMP has some information, more at http://www.horde.org/ingo/ (not sure if that applies).

There are a number of "catches" mentioned in various places, such as if your own address is whitelisted (so of course filters are bypassed), not ceasing checking when a filter condition is met (??IIRC), that filters only apply when webmail is accessed (could be relevant) and failing to apply newly-created rules. None of those affect your case?