[Black Tiger]

@Daddygrim: No, just @hotmail.com, users can register with yahoo.com, gmail.com or whatever free email account.
But most have @hotmail.com. My problems are over, except for users not reading the double notice not to use a hotmail.com email adres which then complaint why their email adress is banned.
But beside that I never had problems with filters again.

There are almost no better ways to deal with spammers, and this methode also deals with users with bad setup spam filters in their hotmail email. It costed me a lot of support which now is turned to free time.
And I get a lot more serious users, most scriptkiddies and weenies use hotmail, so they mostly don't register, no hack can beat that one.