Many ISPs take spam seriously; some do not. To report spam:
Determine the source of spam, discover the netblock owner, and send an email to their
abuse@
address.If a website is advertised, resolve the domain name. Discover the netblock owner and send an email to their
abuse@
address.
Sadly, some ISPs ignore email received at their abuse@
addresses, and others actually bounce email to their abuse@
address.
Note
The spamcop.net
website does a very good job of analyzing email message headers and helps you choose who to send spam report emails.