SMTP is a simple protocol for transferring emails over TCP/IP networks.
This video produced by GoDaddy defines SMTP, explains the way it works.
Mail servers use SMTP to send and receive emails, while email clients usually use SMTP only for sending email messages to a mail server for their further delivery.
An SMTP server is a mail server that only supports the sending of emails. Using one, you can send email from anywhere.
Last Updated: 02.01.2020