The service is a text-to-email product. When you receive a text message to your toll free number, you will receive an email. To reply to the message, simply reply to the email leaving the subject line intact.
You can also utilize the online portal to reply to a message.
If you wish to initiate an outbound text message, you will need to use the online portal.
* Click the "Message Center" tab link in the upper-right corner
* Click "New"
* Enter the number you will send your message to in the "To" field
* Click "Start"
* Enter your message and click "Send"