Spam. Again.. -- and blocking net blocks?

Before the flame begins.. I'm not sure when this started.. Background: We have a downstream ISP, who hosts a website of questionable material. This customer (of our customer) used a third party to spam on their behalf.. Which is a violation of our AUP. (In fact we null0 the /32 in question). Problem: For some reason, spews has decided to now block one of our /19.. Ie no mail server in the /19 can send mail. Questions: 1) How do we smack some sense into spews? 2) Does anyone else see a HUGE problem with listing a /19 because there is one /32 of a spam advertised website? When did this start happening? Regards, Mark -- Mark Segal Director, Data Services Futureway Communications Inc. Tel: (905)326-1570