1. system level ( This includes the SPAM scores, SPM-LOW, SPAM-MED, SPAM-HIGH ) 
2. domain level ( top to bottom ) 
3. user level ( top to bottom ) 

Content Filtering

Content filtering is a great way for System Admininstrators, Domain Administrators and/or Users to perform actions on incoming emails that meet specific criteria. For example, it's possible to use content filters to delete messages with certain attachments (e.g., attachments with a .exe extension), forward messages from a specific email address to another account, move messages to a certain folder or even alter the subject of a message by appending something to it prior to delivery. While content filters are most commonly used to organize email by moving messages to specific folders, they're extremely flexible and allows you to filter messages the way you want to.