How do I deactivate iMessage so I receive messages on my new phone?
In some cases, moving from an Apple device to a different type of device can cause problems receiving SMS messages. This is due to the Apple iMessage setup.
To deactivate on your phone: Tap Settings from the home screen. Tap Messages. Move the iMessage slider to OFF.
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If you no longer have access to the phone, contact Apple Support and they can assist you in deactiving the device.