A lot of people including me are hitting this issue. My Microsoft Account (outlook.com) fails to sync and causes all email apps to crash. When I look at the settings, my Microsoft account, along with linkedin and twitter, are always in Syncing state. It doesn't complete the sync. During that time I can't open any other email apps (exchange, gmail, etc..), they crash and don't open. restart didn't help. I turned on airplane mode and turned on again but issue persists. My Microsoft account somehow doesn't complete sync and causes crash on email apps. Any suggestions on what to do other than resetting the phone?