This article explains how to send a text message to someone else's phone using a smartphone that supports SMS and MMS.
How to send a text message from an email
To send a text message via email, use your recipient's carrier's MMS or SMS gateway with their mobile number as the address. For example, if your recipient's phone number is (212) 555-5555 and their carrier is Verizon, you would address the email to [email protected]. The text in the body of your email will appear on your recipient's phone or other mobile device as a text message.
To send a text message, you need the following:
If you don't know the carrier of your intended recipient, use a website like freecarrierlookup.com or freesmsgateway.info. You can enter the recipient's phone number to look up the service provider and SMS/MMS gateway addresses.