The PureMessage filtering software applies a series of tests to each incoming email. This series of tests determines the probability that a particular message is spam.
If a user is taking part in UWSPAM Quarantining, emails with a probability rate of at least 20% and less than 50%, display this information in the Internet Headers section of each email. For users taking part in UW Spam Tagging, emails with a probability rate of at least 20% display this information in the Internet Headers section of each email. The Internet Headers section of each email lists the probability that an email may be spam in percentage format (i.e. 50%) and as a series of X's, with each X representing 10% (i.e. XXXXX for 50%). .
If a user has chosen to take part in only the UW Spam Tagging service, emails with a probability of 50% or greater are also tagged in the Subject line with [SPAM-H], [SPAM-M], or [SPAM-L] depending on whether their probability of being spam is High, Medium, or Low. Users can then sort or filter their email by the Subject line content to more easily review and delete the unwanted emails.