Greylisting
In approximately one month Rice will begin implementing a new spam control system. Greylisting is designed to complement existing spam prevention systems and offers many advantages over standalone programs. Greylisting will benefit the entire campus community with immediately lower spam levels without an increase in message delivery times.
Since Greylisting works in conjunction with the Rice Blacklist, if you choose to "opt out" you will be opting out of both.
How Greylisting Works
The Office of the Vice Provost for Information Technology (IT) has received numerous requests in the last two years for relief from the overwhelming volume of junk mail received by Rice community members. One set of services that can help block spam and phishing messages from Rice email customers is called Greylisting.
Greylisting works by analyzing three pieces of data associated with each email sent to Rice. These points of data are based off the internet and addresses and associated with all messages that are not usually visible to users. Using this data, Greylisting builds a relationship. If it has never seen this relationship it will reject the email. Normal mail servers will attempt to retry sending the message at which point the Greylisting software will allow the legitimate message. Spam, however, usually originates from applications that do not attempt to resend a message when the spam is rejected. Legitimate email is allowed through with minimum delay while spam applications move on to to the next email address.
Link to the technical white paper: http://projects.puremagic.com/greylisting/whitepaper.html
