FAQ / Server Products

Spam email is coming in with a header From address spoofed from one of our own internal domains. How can I block this?
This is quite common now. An email has two sender addresses - the MIME From address (the address shown on the email) and the SMTP Sender address (or envelope sender). The two do not have to be the same. To block email where the two differ you can use the options in SPAM Blocker/Detection/Senders/Options/SMTP vs MIME Use the Internal options to BLOCK email spoofed from your domain. Remember that some newsgroups and newsletters also address email in this way - so they may also be blocked using this rule.

There are also the following guides: