PureMessage E-mail Filtering

WPI has made the decision to purchase and implement PureMessage. PureMessage is an e-mail filtering system that will be used to identify spam. There was an evaluation period that ended on Tuesday, April 8, 2003. During the evaluation period many users noticed that messages thought to be spam had the string "[PMX:###]" appended to the beginning of the subject line. The subject line marking has now been disabled due to a large amount of negative feedback from the WPI community. WPI's implementation of PureMessage will allow mail recipients to decide what they wish to do with marked e-mail. At this point in time, no messages will be dropped by the spam scanner, all incoming mail will be delivered. Users can decide if they would like to drop messages altogether or to file messages into a "spam" mail folder.

Common Questions

How does PureMessage work?

PureMessage uses a set of rules and heuristics to assign a probability that a message is spam and thresholds can be set to either tag or block messages that exceed a threshold. At this point in time, no messages are actually being blocked. However, some useful information is added to the header of the messages that can be used by the end user to reject or file messages based on these headers. Messages that pass through the PureMessage filter and have spam-like characteristics are marked with the following:

X-PerlMx-Spam: header - The X-PerlMx-Spam: header is added to the message. This header contains three pieces of information:

Gauge - This is the probability that a message is spam. The gauge is listed with an X for each 10% and an I for each 1%. For example, if the probability is 32%, the gauge will be XXXII.
Probability - This is the same as the gauge field but is just listed as a numeric probability.
Report - The report field lists the rules this e-mail message matched in the spam rules.

If you would like more technical information regarding this product, please visit the PureMessage web site: http://www.sophos.com/products/es/gateway/pm-unix.html

Can I turn off PureMessage so that my mail is not scanned for spam?

No. Mail is scanned and marked at the server level. All mail that passes through the WPI e-mail servers will be scanned and marked accordingly.

Does this mean that someone is reading all of my e-mail?

No. WPI is committed to user privacy. The filtering process is completely automated. It does not require intervention by the system administrators.

Can I filter my e-mail based on the PureMessage SPAM marking?

Of course! The decision to purchase PureMessage was driven by feedback from users who were interested in filtering their own e-mail. Users will be able to take advantage of the PureMessage marking to automatically filter their e-mail based on their own preferences. There are a number of ways to accomplish this. Please select a CCC-supported e-mail reader below to learn about using PureMessage marking for filtering your e-mail automatically:

Maintained by itweb.
Last modified: Jun 23, 2010, 12:53 EDT