HELP!

I'm looking for a way to block specific e-mail addresses from my broadcast
lists.  Is there a way that I could build a file that my lists would check
against prior to sending the e-mail?

I work for a company that is a direct mail distributor.  We are looking to
leverage our customer base of email addresses to mail certain "offers" to.
We also have a few other lists that are of newsletter/information nature.
If I have someone call in and request to be taken off the list, I want to
make sure we don't mistakenly mail to them in the future.  Currently we're
housing the email addresses in a customer database and don't have the
capability to suppress them at that stage.  We're doing an extract and using
ListServ as a vehicle to mail only (on specific lists)...  on the newsletter
side, listserv is doing the email address management.

Can you provide any insight?

Thanks,
Tressa Graves