Email has been and continues to be one of the most widely used communication tools in the world. This is due in part to the fact that email is versatile, fast and easy to use. More and more people are turning to email as their primary form of communication.

However, as email usage has increased, so too has the amount of email that needs to be handled. This has led to the development of SMTP, or Simple Mail Transfer Protocol, which is a protocol used to send and receive email.

SMTP is a TCP-based (connection-oriented) protocol that uses ports 25 and 587. It uses a client/server model in which an email server accepts email and stores it in a queue. The email server sends the emails out to the email addresses that the user has entered in their account.

In addition to handling email, SMTP is also used to send and receive email via HTTP. This is done using DNS name resolution. The email address that you are using to send and receive email is associated with a DNS name. The email server uses this DNS name to connect to the mail server of the recipient.

SMTP has been around for a long time and continues to be a popular protocol. Its use is increasing and will likely continue to do so in the future.