What is SMTP Messaging?
SMTP is the standard protocol for electronic mail (e-mail) transmission across the internet. It is also commonly refereed to as "Email To SMS" or "Standard Delivery" text messaging. Most email software is designed to use SMTP for communication purposes when sending email. There are two other protocols - POP3 and IMAP - that are used for retrieving and storing email.
SMTP provides a set of codes that simplify the communication of email messages between servers. It's a type of shorthand that allows a server to break up different parts of a message into categories the other server can understand.
To send a text message via the SMTP method, all one must do is attach their phone number to the beginning of of the carriers SMTP email address and send it just like any other email.