Greylisting Key to Blocking more Spam



June 20, 2005 -- DRC Consulting, a premier anti-Spam solutions provider based in Zurich, Switzerland announced today immediate support for Greylistingin its flagship anti-Spam SMTP proxy server.

"Greylisting is an important emerging mail control function which makes clever use of the SMTP mail protocol to thwart low tech mail sending programs. Such programs are often included in mail worms or in mass mailing software." said Darren Crocker of DRCC. "Greylisting is highly effective at lowering your unwanted mail load because it operates at the very beginning of a mail conversation and has no need to look at the contents of a message. A 'greylist whitelist' can be configured to avoid greylisting certain domains or users or hosts that you feel shouldn't be subjected to the initial small delay."

Greylisting works by telling the sending mail server or hijacked home PC that it temporarily cannot accept the message and should try again later. This re-try mechanism is part of the SMTP mail standard so should be fully supported on SMTP any standard mail server. Zombies, worms and other low tech mass mailers usually do not support this standard function and therefore never attempt to re-send the Spam or virus laden message. The greylist system keeps track of sender credentials and allows future messages to pass unhindered. Only the first message from a particular sender/host combination is slightly delayed.

Since nsj works on any standard Java platform, it's a low cost and highly effective way to add this additional layer to your existing SMTP mail environment. In addition, nsj offers many more advanced mail security features, a user based quarantine and support for sender authentication protocols such as SPF and DomainKeys.

More information on greylisting can be found at http://www.greylisting.org.

More information on nsj, and a free trial download can be found at http://www.drcc.com/nsj





Greylisting Key to Blocking more Spam