Is there some way I can set my preferences or message rules to block mail from addresses that are not on my contact list?

Go to Tools->Message Rules->Blocked Senders List and click on the Mail Rules tab. In there, click the New button. Under there, click "Where the From Line contains people". This will pop up on the bottom. Click the blue underlined words. Click on Address Book and add everyone on your address book that you want to receive mail from.

Then click Options. Put #1 to "Message does not contain the people below" and put #2 on "Message matches any one of the people below".

Click okays until you're out of it all.

If this doesn't work, ask George.

Thanks! Hope this works!