stopping my server from spamming

[Tamouh H.]

> 
> I have been blacklisted for spamming and I am attempting to 
> ascertain the source.
> 
> I have a few networked windows boxes which route through a 
> FBSD server. I also have around ten off-site users who send 
> mail via my port
> 26 - using smtp password authentication. How do I determine 
> which email going through the server is spam, and therefore 
> identify the source?

This is more of a question geared towards your mail server application than FreeBSD. You should check your mail logs. If you want better advise, you may want to provide more information on what mail server are you running, and what did you do to prevent SMTP relay.