More about Spam Detection Service

Channel

Channel - September 2004, Issue No. 41
WWW & Server Technology Team

More about Spam Detection Service

Since our rollout of Spam Detection Service in Sept 2002, over 2500 HKUST staff and students are now using this service in getting rid of annoying spam messages. The feedbacks we received so far are very positive.

Spam is really a headache to most of us. Technique like joe-jobbing, i.e. the practice of spoofing your email address as the sender's e-mail address in the spam message, is getting common and irritating nowadays. Up till now, there is no definite way to tackle and stop this kind of problem. No matter how good your own web sites are being maintained, there are still many many computers around the world that are not properly managed and are being hijacked by spammers to send spam.

Our Spam detection engine has been employed 2 years ago in attempt to recognize potential spam messages based on a set of heuristic rules. Suspected spam messages would be delivered to a special email folder (called AutoTrash) of the recipient. So far, this looks to be an effective way to help our users to isolate most of their spam messages and get rid of them easily. After hearing feedbacks from our users and to keep up with the latest technology, the following upgrade has been performed in the recent summer :

New Anti-spam Technique - Distributed Checksum Clearinghouse
Our spam detection engine has been upgraded to support a new anti-spam technique, Distributed Checksum Clearinghouse, or DCC. DCC is a network service that provides an indication of whether a message has been sent in bulk and DCC anti-spam rules will assign a weight to the message to increase its spam probability. This has found to contribute significantly to our anti-spam accuracy.
Choice of deletion days for AutoTrash folder
In the past, suspected spam messages in AutoTrash folder will be deleted by the system automatically after 30 days unless the user saves them to another folder. Now, our users can have a choice of 7, 14 or 30 days for this automatic deletion days for their AutoTrash folder. Please logon to HKUST iMail Personal Settings to make your choice.

If you would like to try out our Spam Detection Service or know more about it, please refer to the following web site for details:

http://www.ust.hk/itsc/email/spam/

Last but not least, spammers will often run their messages through a variety of spam detection engines available in the market to see how best to defeat them and will then adjust the content of their spam messages accordingly. It is just like a game of cat and mouse in which the mouse may get smarter at evading the cat. To benefit our HKUST community, we will keep aware of the latest trend or solutions in handling this worldwide issue.