Postgrey

Postgrey is a Postfix policy server implementing greylisting.

When a request for delivery of a mail is received by Postfix via SMTP, the triplet CLIENT_IP / SENDER / RECIPIENT is built. If it is the first time that this triplet is seen, or if the triplet was first seen, less than 5 minutes ago, then the mail gets rejected with a temporary error.

(Greylisting is a method of blocking significant amounts of spam at the mailserver level, but without resorting to heavyweight statistical analysis or other heuristical (and error-prone) approaches. Consequently, implementations are fairly lightweight, and may even decrease network traffic and processor load on your mailserver).

Postgrey 1.32

Price Free to download Size 35KB License GNU GPL Developer Open Systems AG Website postgrey.schweikert.ch System Requirements Perl ≥ 5.6.0 Net::Server IO::Multiplex BerkeleyDB (Perl module) Berkeley DB (library ≥ 4.1) Support Sites: Mailing List, Tutorial Selected Reviews:

Features include:

• Safe database
• Automatic maintenance
• Lookup by subnet
• Whitelists
• Auto-whitelisting of clients

Last Updated Sunday, September 21 2008 @ 05:07 AM EDT