1. right click on Local Folders, select New Folder. Name the folder Potter National.

2. repeat, name the second new folder Potter Northwest or Potter Local.
3. Go to Tools à Message Rules à Mail:

4. Check the appropriate boxes to find messages that arrive with “[WWP]” in the subject line and move them to your Potter National folder. (Update: You may instead want to find messages where the To line contains "WWPotter@yahoogroups.com"; this is a preferable approach, made possible by changes in the listserv configuration since these instructions were first written. The instructions are otherwise unchanged.)

Click OK.
5. Repeat for the Potter NW list serv, but instead of keying on [WWP] in the subject line, select on sail@tx3.com in the To line:

Click OK.
6. Click on Addresses in the Tool Bar and create outgoing email addresses for the two lists so that you can easily initiate new messages to the appropriate one (when you’re not replying to someone else’s message):

Repeat for the Potter National list, the email address for which is wwpotter@yahoogroups.com.
7. Once you get it set up, you’ll probably need to fiddle a little with the Message Rules Properties to get it to work just right. Most commonly, I find I have to make adjustments in how I have the rule configured to hit on To, or From, or Subject, depending on how the particular listserv server is configured, but the above should work and any adjustments should be easy.
Call me if you can’t figure it out: (425) 823-9279.