How do I register my phone to use it for Messenger?
To get IMs as SMS messages:
- Click the Forward... button at the top of your Messenger window.
- Click Forward offline IMs to, then click Add a phone number.
- You'll be guided through a few easy steps for entering your number.
If you already have a registered number, it will be displayed in the “Forward offline IMs to” menu, and you can simply click it to start IM forwarding.