Tarpitting

Tarpitting is the term given to a process which combats spam and abusers by making it difficult to send large volumes of mail.

If Tarpitting is enabled and a client becomes blacklisted, rather than immediately refuse the connection or refuse the recipients, they are accepted but delayed substantially.

This does not add any load to Mailtraq, but prevents the client from delivering additional messages to other servers. After all the recipients have been listed, Mailtraq will still refuse the message.