Spammers Relaying Through Bounces

[kentborg at borg.org (Kent Borg)]

I got a bounce from AOL including the URL
<http://postmaster.info.aol.com/errors/554rlybd.html>.

It seems they consider me a relayer of spam, and I think I know why:
spammers send e-mail from "Person X", to "Bogus Person Y" at my
domain, "Bogus Person Y" doesn't exist, so qmail bounces the message
back to "Person X".  They then do this for a lot of different persons
as "Person X", and turn me into a spam house.

How can I stop this relaying?


-kb