To enable this option, open Gmail, click on Settings, then go to the Labs tab. Scroll down until you see "Text Messaging (SMS) in Chat" and select Enable and Save Changes.11 Dec 2008
Can you get an SMS for Gmail?
When sending an email, just click on the 'Gmail SMS Alert' icon on the bottom, and you will get an SMS text alert when your email recipient replies back to you. You can also set up SMS text alert rules for when you receive emails. with the word “urgent” in the subject title, for example.