Field

Description

Active

Enables the use of RBL servers.

RBL Server list

Check the box against each RBL server you want to use.

NOTE: You should limit the number of servers you choose to query for RBL processing as this can have a detrimental effect on your server performance. Each server would have to be queried at least once for each incoming message, adding overhead to the processing.

If a number of DNSBL hosts exceeds the limit of 4, a warning message is displayed.

RBL contains a list of IP addresses whose owners refuse to stop the proliferation of Spam from their servers. The RBL usually lists ISPs whose customers are responsible for Spam or email servers that are hijacked by spammers to send Spam.

NOTE: Extended RBL codes are supported, see http://www.us.sorbs.net/using.shtml for further information.

If you use dnsbl.sorbs.net as your RBL, it will return a code that signifies which blacklist(s) contained an entry.

For example

127.0.0.3 is returned for an open SOCKS Server

127.0.0.5 is returned for an open SMTP Relay Server

NOTE: There are two dnsbl.sorbs.net items in the list (marked (A) and (B)). There are two different rules, both using dnsbl.sorbs.net – if you decide to use it, tick only one of them.