Junk email filtering is a two-step process. Each incoming message from outside George Perimeter College is given a "spam score" and then either placed in your Inbox (if it has a score below your spam threshold) or placed in a junk-mail folder (if it has score higher than your spam threshold). You choose the spam score threshold value in the Email Detection Measure (EDM).
When messages arrive at GPC, they are scanned with a system called ProofPoint Pure Message and given a "spam score" ranging between 0 (probably not spam) and 100 (almost certain to be spam). The spam score is added to the message in a special line in the message header. This line is usually not shown.
The message then goes to the email servers.
· If you have spam filtering turned off, the message simply goes into your Inbox folder (or some other folder if you have other email filters set up).
· If you have spam filtering turned on, any message with a spam score higher than your chosen spam threshold is placed in a special email folder named "junk-mail". Any messages in the junk-mail folder that are older than seven days are automatically DELETED
Identifying Junk Email
PureMessage looks for message characteristics that are common to spam messages, including the following:
Key phrases such as
"Special One-Time Offer,"
"Call Now," "Act Now,"
"You Have Won...,"
"Human Growth Hormone," etc.
Inconsistencies or errors in the header information Characteristics of the text, such as "shouting text" (all capitals) The email distribution agent used to send the message
Characteristics of the route the message followed in the Internet to reach the GPC
"From:" and "To:" header fields being the same (often an indication of a fake From: address)
The scoring system is regularly updated by PureMessage to improve its effectiveness and deal with changes in the characteristics of junk email over time.Many aspects of the message are considered in coming up with the final spam score. In practice, the scoring system has been found to be quite effective at identifying what most people consider to be junk email.
Still, just because a message looks like spam to PureMessage does not mean that it is spam. You may choose to receive marketing email messages from a company you purchased a new computer or a book from, for example. Also, some responsible organizations you may want to hear from use the same email distribution programs as spammers or might format their messages in spam-like ways. To be sure that you do not lose messages you want, it is important to regularly check your junk-mail folder once you turn on spam filtering. Any message in your junk-mail folder that is more than seven days old will be automatically and permanently deleted!
Is the GPC blocking some spam?
Yes. Email from certain sources that exclusively send large amounts of spam are blocked and discarded before they enter the GPC email system.
Is scanning for viruses also being done?
Yes, email messages are also scanned for viruses both as they come in to GPC email system and as they go out to the world.
Does the spam scanning mean my email will be delayed?
Scanning will typically delay messages by only a second or two.
What can I do if my own messages get high spam scores?
Look at your email message to see if it has characteristics that, to PureMessage, look like spam, and edit your message accordingly. You can also forward a copy of the message to email@example.com
for their suggestions.
Does this mean that GPC is reading my email?
The scanning is done by a program checking for the presence of specific text strings and other characteristics of messages many people consider to be spam. GPC OIT staff themselves do not inspect, monitor, change, or delete email.
What should I do if I find spam that is assigned too low a score?
Identifying spam is an inexact science. The PureMessage criteria are constantly evolving on the basis of their experience with a very large number of emails, so it represents a generalized understanding of what spam is and how to identify it. GPC OIT can't directly make adjustments to the scoring system, but does work with the vendor to identify needed changes. If you come upon a case that seems to be far out of line with expectations, you could forward an example (including the full email header) to firstname.lastname@example.org.
Why did GP OIT choose PureMessage to do the spam scoring?
GPC OIT had done junk email evaluation and filtering software for many months and settled on PureMessage for a number of reasons:
The way PureMessage works fits in well with how the GPC email system works, allowing GPC OIT to provide a central, high-quality, high-speed spam identification system without major changes in the existing infrastructure.
ProofPoint which makes PureMessage, has demonstrated its ability and intention to keep the spam scoring system up-to-date.
No changes are needed in the email client program you are already using to use the Junk Email Filtering function.
PureMessage has received good reviews from other higher education institutions.