I have an iMac and a MacBook. My wife and I each have a home user account/login. We share the Address Book data by having all four "accounts" (one each on each machine) set to synchronize data via .Mac. No matter how many times I delete com.apple.mail.plist in ~/library/ preferences and ~/library/Mail, and delete the account in her Mail preferences, and make sure that System Prefs-->.Mac-->Sync--> "Mail Accounts" is unchecked on her accounts, every time we start up Mail in her account, my .Mac address information is still in there. (She uses AOL webmail for her own email). Anybody have any ideas as to whether there is another location in the System folder where those preferences are kept/backed up? Obviously, something is repopulating those preferences each time. Thanks :-)