Unfortunately, the nexus/gpe (googlemail.apk) email app does not update the Moto x app (aosp mail.apk), so if you use the mail app for exchange, like I do, it won't pair with the correct exchange.apk, so there is no exchange support.
Edit: apparently you can have exchange support by installing the Google exchange app. I ripped one from my nexus 7 2013 on 4.4.3 and installed as a normal app. It works just fine. I disabled the system mail and exchange just to be on the safe side. I'll upload the apk here shortly.