Actually, you need to ask your upstream provider to fix this problem
since they are the ones who ultimately have the real power when it comes to
terminating spammers. Of course, if they're not interested in getting
spammers off their systems, then perhaps you need to find an ISP who both
takes the spam problem seriously, and doesn't permit the theft-of-service
tactics that spammers just love to employ.
Spam-friendly ISPs are regularly blacklisted in SPEWS.org. The
smarter ISPs who understand the basics of business understand the
importance of not allowing spammers on their network.
For more perspective on this issue, the following document will
explain the "divide" that has been growing between ISPs:
Good-bye to middle class ISPs
http://www.inter-corporate.com/spam/classes.html
Please feel free to include your ISP's response regarding your request
to have them terminate their spamming customers' accounts.
--
Sir Randolf, noble spam fighter - r...@8x.ca
Vancouver, British Columbia, Canada
Please do not eMail me directly when responding to
my postings in the newsgroups.
Sending eMail to other SMTP servers is a privilege.