You can choose to insert a Username in all of your messages.
If you send a Standard Delivery message and your username is 'txtmsguser', your 'From' information would appear as "From: firstname.lastname@example.org.' Please note that this email address cannot be deleted from messages. The nature of Standard Delivery technology does not allow for removal of this format or information from your message.
If you send your message using Express Delivery, the text messages received will come 'From' the short code number 25827, and your username will appear at the beginning of the message (without domain information). For more information, click here.