Google is adding a new experimental to Gmail that let you send text / SMS messages to mobile phones using the built-in Chat functionality. To turn it on, go to the Labs tab within Gmail’s settings, or just click on the little green Erlenmeyer flask icon next to your e-mail address at the top of the page in Gmail. Once the option is turned on, start typing a phone number into Chat’s search box and you’ll see the option to send an SMS.
If you don’t see the option right away, check back later — Gmail product manager Keith Coleman, says it’ll be made available in Gmail Labs to all Gmail users by Thursday evening.
The first time you send a text message, it will appear on the person’s phone as coming from a number in the 406 area code. Google has made several thousands of these numbers available for Gmail users, and once a number is associated with your account, all of the text messages you send through Gmail will come from that number.
The 406 number works both ways, so your friend can reply to you via text message. Also, your friend can save that number in their phone as belonging to you, and they can even use it to initiate new chats with you.
Here’s how to send messages:
- Enter your contact's name in the 'Search or invite friends' box in Chat, and select Send SMS from the box of options that appears to the right of your contact's name. Or, if you already have a Chat window open for this contact, just click Video & more, and select Send SMS.
- In the dialog box, enter a phone number in the 'Send SMS messages to this number' field. For now, this feature works only on United States phone numbers. If you're outside the US, you can still use it, but you won't see the SMS option in Chat until you enable it manually in the Chat settings page.
- Click Save.
- A Chat window appears. Just type your message as you would normally. When you hit Enter, the message will be sent to the phone number you entered.
If your contact replies, the text message response will appear as a reply in Chat. These conversations are stored in your Chat history just like regular chats (but keep in mind that you can’t go off the record while communicating via SMS).
More info: Help center articles for Gmail SMS