SYMPTOMS

When a mailbox, domain or post office is disabled within MailEnable an inbound message a disabled account will be accepted by the system before being rejected by the Post Office Connector. The bounced mail message can be deemed as being a form of spam called backscatter.

More on backscatter can be found here:

http://www.mailenable.com/kb/content/article.asp?ID=ME020492

CAUSE

The cause is due to the postoffice connector service creating the bounce message instead of the SMTP service. When this feature is used it may mean you are replying to an address which did not send the email originally.

SOLUTION