Any mail admins here?

I have two spam filters that relay outbound mail for a few dozen companies,
and as such generate a fair amount of traffic. We are fairly strict with
the spam filtering on outbound mail, but somehow end up blacklisted by
ATT/Prodigy/Bellsouth a few times a year.

Got this a few months ago, posting publically so it makes it into the archives
for the next guy.