If you're having issues with the app and your exchange email. More than likely you will have to delete/uninstall the app off of your mobile device. Make sure if you're using iPhone, delete it off the device not just the home screen. Once deleted, reinstall it and try re-adding your account again.
My issue was that it seemed to cache something and the password I would try to update would not let me login. It would prompt me "Unable to login" check email and password and try again. I tried about all other trouble shooting attempts and this was the only solution that solved it.
Hope this helps some others as well!
TJ
