Prerequisite: Before you can send text message from your email; you need to setup Email to text service with MMS enabled.
Follow STEPS to setup email to MMS service
To send a MMS Picture Message, address an email to the mobile phone number:
Email TO: 17321234567@Text2Email.net
The mobile phone receives a text message, to which they can reply using a text message.
Reply text messages are then forwarded to your email account:
To send to a text message to group of people, include all their numbers as:
Email TO: email@example.com;firstname.lastname@example.org;email@example.com