When you add an Exchange account using ActiveSync on an Android phone, some phones will begin forwarding a copy of every SMS message (e.g., text message) that the phone receives to your email account. This feature will vary from phone to phone.
To disable this feature:
- On the phone, open the Email application.
- Tap Settings, then tap Microsoft Exchange ActiveSync in the Accounts group.
- Next, tap Settings under Common settings group, then tap your email address.
- Scroll down and under the Server settings group, uncheck Sync SMS (or Turn off Messages)