POP3 - Black Lists
POP3 Account Properties - Blacklists
This tab, accessed from the POP3 Account Properties dialog, enables the blacklisting facilities to be configured for this instance of the Remote POP3 Service.
Explicit Black and White Lists
Click on these buttons to enter lists of client IP addresses, sender e-mail addresses and recipient e-mail addresses to black list or white list (respectively). Clients that send a message which matches the black list, or who are blacklisted by one of the configured DBLs, will be barred from sending any further messages for a period of time.
DBL (DNS Black Lists) servers can also be configured, which allows Mailtraq to use public black lists to determine whether or not a client should be allowed to send messages to Mailtraq.
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.
See the Tutorial here: http://info.mailtraq.com/dbl-tutorial