1. In Outlook Express, go to Tools | Message Rules | Mail. The Message Rules window will appear, and if you have never made a message rule before, the New Mail Rule window will automatically pop up. (If it does not, click on New).
2. In the Conditions section, put a check next to "Where the message body contains specific words".
3. In the Actions section, put a check next to "Delete it".
4. In the Rule Description section, click on the "contains specific words" link. The "Type Specific Words" box will pop up. Type the word or phrase by which you want to filter mail into that box and hit Add, then hit OK.
5. Type a descriptive name for the message filter in the Name of the Rule box. Hit OK to save.
6. Click OK to close the Message Rules window.

A filter set up as described above will automatically delete any incoming mail which contains the word you entered in step 4. You can modify your rules to suit your needs. For instance, you can filter mail based on the subject line of the message, the sender's address, or other criteria by changing the entry in step 2.