Nolisting (Paperback)

High Quality Content by WIKIPEDIA articles! Nolisting is a method of defending electronic mail users against e-mail spam. The idea is that by having a non-existent primary mail server and a working secondary mail server, attempts to contact the primary mail server will always fail. If the mail is sent by a correctly configured email server, the sending server will then try to contact the secondary mail server, and should succeed. Spammers frequently use custom software that does not retry higher-priority MX records. Nolisting refers only to a configuration involving an unresponsive single primary MX with one or more functional lower priority MX servers. This configuration has been proven to be very safe. Variations involving multiple unresponsive MX records do not meet this definition (and there is little evidence supporting the effectiveness of such an approach).