How to access and/or delete an invisible Exchange account?
I think I have encountered a similar issue before. Not sure how I fixed it, but


see if you have a Device Administrator for Exchange. In the Samsung Galaxy S4, it's in Settings &gt; More &gt; Security &gt; Device Administrators. Uncheck / Remove it there, do a restart, and see if that helps.
or:  Go to your application manager, and swipe to the ALL section. Then look for the Email app. Click that and do a Clear data and/or Clear cache. Also, look for the Exchange services app, and do the same. Restart, and see if that helps. 


Based on Asker's feedback, the second approach fixed the problem. He also cleared the GMail app, although it's not necessary.