Not sure if anyone else had this . . . last night upgraded to beta 3 and then today the mail app started duplicating emails from one folder to another, it created 9000 and if i deleted any they would reappear, it pushed to all my iCloud devices where I deleted the 9000 emails but they remained on the phone, wouldn't delete and then it pushed them back to the cloud where they reappeared twice more, so the phone generated 27,000 email copies. In the end only way to clear them was to restore back to Beta 2 . . . . It's a beta!