- from w3schools.com
The SMTP protocol is used for the transmission of e-mails. SMTP takes care of sending your email to another computer.
Normally your email is sent to an email server (SMTP server), and then to another server or servers, and finally to its destination.
SMTP can only transmit pure text. It cannot transmit binary data like pictures, sounds or movies.
SMTP uses the MIME protocol to send binary data across TCP/IP networks. The MIME protocol converts binary data to pure text.