WebMail Spam Filter Setup

This page describes how to set up filtering of unwanted commercial e-mail ("spam") on your account within CIS Unix WebMail. Setting up spam filtering directs the system to divert probable spam to a separate mail folder in your account (IN.spam), while non-spam mail goes to your INBOX as usual.

Details: Incoming e-mail to CIS Unix accounts passes through the SpamAssassin^TM mail scanning program. SpamAssassin uses a number of heuristic tests to score each message it sees: the higher the score, the more likely the mail is spam. Special tags are added to each message before it is delivered to your account containing the score and SpamAssassin's guess as to whether the mail is spam or not. Mail filtering uses these tags to decide whether your mail goes in your normal INBOX or is diverted to the IN.spam folder.

Important: While SpamAssassin does a very good job guessing whether incoming messages are spam or not, you shouldn't forget that a very good guess is still a guess. SpamAssassin will probably classify a relatively small fraction of non-spam messages as spam ("false positives"), which will be delivered to the IN.spam folder. Conversely, it will probably fail to correctly detect a fraction of spam messages ("false negatives"), which will wind up in your INBOX. CIS will not be responsible for incorrect classification of incoming messages, either false positives or false negatives.

WebMail (and most other mail programs, like Alpine, and most IMAP mail clients) will allow you to access the IN.spam folder in the same way you access your other mail folders. We suggest you look through this folder periodically to quickly delete actual spam and (possibly) read the messages SpamAssassin has mistakenly classified as spam.

More information on using SpamAssassin for spam filtering is here.

Here is the WebMail method for setting up a spam filter:

1. If necessary, log into WebMail here, or via Blackboard.

2. On the left-side menu, click the plus-sign-in-a-box icon next to the 'Mail' menu item, if necessary, to display its subitems.

   

3. Click the 'Filters' icon under 'Mail'.

   

4. If you're lucky, the resulting page might already have the "CIS Unix Spam Filter" rule, but it might be disabled.

   

   In this case, click the red text to enable the spam filtering rule, and you're done.

   (If you don't see the red text, the spam filtering rule is already enabled, and you were done before you started this.)

5. If you don't have an entry for the CIS Unix Spam Filter rule, you need to put it in yourself. Click the "New Rule" button, and you should see something like this:

   

6. Type "CIS Unix Spam Filter" in the Rule Name box and choose 'X-MailScanner-SpamScore' from the first pulldown menu.

   Now the rule should look like this:

   

7. In the next pulldown, choose 'Begins with' and type five (5) 's' characters in the next box.

   Now the rule should appear this way:

   

8. Almost done. Under the Do this: pulldown menu, select 'Deliver to folder:' and type 'IN.spam' in the box that appears next to the pulldown

   When you've done that, the rule should look like this:

   

9. Check one last time that the rule appears as above. If it doesn't, go back and fix things. But otherwise, click the 'Save' button and you're done.

Last modified: 2009-09-18 13:42 EDT Paul A. Sand pas@unh.edu