From Mac Mail menu
1. Select Mail > Preferences
2. Click on Rules Tab
3. Click Add Rule
4. Select the drop menus with the options for what you want to do
5. once done, press ok
Specifics on how to block a sender go to this link:
http://email.about.com/od/macosxmailtips/qt/How_to_Block_a_Sender_in_Mac_OS_X_Mail.htm
