Simple Mail Transfer Protocol
SMTP is responsible for sending email messages. This protocol is used by email clients and mail servers to exchange emails between computers.
A mail client and the SMTP server communicate with each other over a connection established through a particular email port. Both entities are using SMTP commands and replies to process your outgoing emails. Thanks to the Simple Mail Transfer Protocol, messages can be sent from the same account on different email applications.
It is a part of the application layer of the TCP/IP suite and plays a crucial role in the process of email delivery. SMTP is used primarily to set up communication rules between servers, allowing them to send and receive email messages.