I was following the directions in a great post when I got to the step for selecting the name of the script to run. I have VB code in ThisOutlookSession, but for some reason, the name of the procedure does not appear in the "Select Script" box. I can step through the code in debug mode, so it seems to be syntactically correct. What can be causing it to hide?
You probably have the wrong parameters in the script. Are you just passing in a MailItem? e.g.
Once you've compiled it (Debug|Compile), it should show up in Outlook rules as an option. Note that if the parameters are wrong (i.e. you don't pass in just a MailItem) then it won't appear.