From Apple's website: http://www.apple.com/macosx/features/mail/ Stay in contact The perfect companion to Mail, the Panther Address Book keeps you from losing contact. Say you move, change your email address, or get a new cell number. Check a single box in Preferences and Address Book will automatically notify every one of your contacts as soon as you finish updating your personal information. Is there any way in apps to keep certain features from even existing? The only reason I ask this, is because sometimes my prefs are accidentally deleted or set back to their defaults, often when I am running very low on disk space ( < 300mb). I have this feeling at some point I will change my address book entry, and it will accidentally send 100 emails out, to people who could care less about my info. Also, the fact that mail.app now incorporates Safari's html engine, could this be an entryway for a new breed of viruses, on the mac side? I know OS X is secure, but what concerns me is the tight integration between all the iApps, and the possibility that at some point, some java application could launch, and do something. I leave it at this, because I have no clue what that something is. I don't have any unnecessary services running, so on that front I feel secure. MS screwed up, one reason being the scripting capabilities (VB, macros) of it's applications.