Mark Roberts wrote:
Are you rejecting at SMTP (I think that's the proper way of describing it) rather than bouncing the entire email including message body? The reason I ask is that some spammers are using servers that include the message body in the bounce as de facto relays: Spammer wants to send spam to [EMAIL PROTECTED] but wants to be untraceable (and avoid Joe's IP blocklist), so he forges [EMAIL PROTECTED] into the *from* line of the header and then mails it to a non-existent address at your domain, knowing that your server will "bounce" it all (including the message body with the spam) to [EMAIL PROTECTED] - right where the spammer really wanted it to go. My university's mail server was configured this way until it became widely blacklisted because of it.
Bouncing (Rather than rejecting at the SMTP Conversation) should only be configured if the server in question is a secondary MX for offsite domains (Usually for ISP's who provide Secondary MX services to their customers).
-Adam
