Filtering Spam in Your Email

How Spam Filtering Works

The University of South Carolina has introduced spam scoring for all email that is received by Gamecock E-Mail (GEM) from an address outside the University network. The score is based on a combination of factors, including the distribution list, the subject line, and the domain from which the email originated. The more likely the email is Spam, the higher the score.

Emails which receive a score of 3 or higher are tagged as they are delivered to your inbox. The score is appended to the subject line of the email as follows:

{SpamScore: sss}

Note that the number of times the character “s” occurs after the colon indicates the score. For example, an email which scores a 7, would have the following text appended to the subject line: {SpamScore: sssssss}.

It is possible that some emails that you receive are spam and will not be scored. It is also possible that some emails may be scored as spam, but are actually emails that you wish to receive. The determination of what constitutes spam is not exact and is prone to error. We recommend that you configure a spam filter to save emails scoring 3 or higher in a separate “junk” or “spam” email folder. You should review the contents of that folder periodically to ensure that all emails truly are spam and then delete the contents of the folder.

If you find that some emails are incorrectly tagged as spam, you may want to tune your filter rule for a higher score. For example, if you subscribe to vendor-sponsored mailing lists, you may find that some of those messages or emails will be scored inadvertently as spam.

Creating a Spam Rule

You can manage your spam by applying a filter or rule to your incoming email. We recommend that you begin with the minimum score of 3 and move these emails to a folder specifically designated for spam. Please periodically review the contents of this folder to ensure that all emails are indeed spam; once you confirm that the contents are actually spam, please empty the folder so that it will not grow too large.

Most email clients provide a tool to sort email into various folders based on the sender, the addressee, the subject line, or the contents. Please check the documentation for your particular email client to determine how to configure a rule for your inbox. Please note that some clients may require that a specific mail protocol be used before filters or rules will apply.

The basic steps for configuring the rule are as follows.

1. Create a Folder Designated for spam.
   You might want to label it “spam” or “junkmail” or something similar for ease of use.
   
   

2. Create the Rule.
   Configure your rule to move emails to the “spam” or “junkmail” folder for any email in which the subject contains the string:
   
   {SpamScore: sss
   
   The number of times “s” occurs in the string denotes the score. If you prefer a higher score, then simply write the string with the appropriate occurrences of the character “s.”
   
   

3. Test the Rule.
   Test your rule by sending yourself 2 test messages with the following subject lines:
   
   Test Message 1 with score of exactly 3 {SpamScore: sss}
   
   Test Message 2 with score higher than 3 {SpamScore: sssssssss}
   
   Both should be moved. If you find that the rule is not working, you may need to change the pattern to match. Some email software will match only whole words and will match only the full string “sss…..” as opposed to a portion of the string.
   
   In this case, you might want to try a “wildcard” character in the pattern to match. Please check the documentation for your email program to determine how “wildcards” apply. Frequently, the asterisk (*) is used as a “wildcard” which will match one or more characters in a string. If the asterisk (*) can be used to match any group of characters, you might want to configure your rule to move any message whose subject contains the string:
   
   {SpamScore:*sss
   
   Unfortunately, how pattern matches are performed and how “wildcards” apply differ from one email program to the other. It may take some trial and error to determine the appropriate rule.
   
   
4. Order the Rule.
   Typically, you will want your spam filtering rule to be the first to be executed. If you have configured multiple rules, make sure that the spam rule is in the correct order for execution.
   
   
5. Periodically Check the “spam” or “junkmail” Folder.
   Remember to check your “spam” or “junkmail” folder periodically, to determine if any emails that you wished to receive were inadvertently filtered; if so, you may want to tune your rule for a higher score. Remember to delete the contents after checking for valid emails so that your mail folders do not grow too large.