Email marketers send a large volume of outgoing emails on a daily basis. Understanding how Simple Mail Transfer Protocol (SMTP) works and what happens during an SMTP dialogue is important to resolving common issues that arise during this process.

What is SMTP (Simple Mail Transfer Protocol)?

SMTP or Simple Mail Transfer Protocol is a digital slander standard method by which email clients exchange messages. Like other protocols, SMTP includes a set of rules that allow information to be exchange between various accounts on email clients.

SMTP is one of the most widely use protocols messaging tips for connecting with worldwide. In fact, SMTP is the only proprietary protocol use to send emails between servers, and many of the world’s most popular email clients, such as Outlook and Gmail, use SMTP.

Therefore, email marketers need to have a strong understanding of the purpose and functions of SMTP and SMTP relays.

Extend SMTP commands

Extend Simple Mail Transfer Protocol or ESMTP is an extension of SMTP that aims to provide higher levels of functionality and security to help protect servers.

ESMTP has a wide range of useful features including SSL encryption, multimedia file attachment, and sender authentication.

Here are some of the most sault data common extend SMPT commands:

1. STARTTS

The client issues the STARTTLS command to initiate a TLS (Transport Layer Security) handshake with the server. This initiates a secure SMTP session between the two parties.

In response, the server sends code 2220 to indicate that it is ready to begin the SMTP conversation. After that, the client will continue with the HELO or EHLO command to initiate the SMTP conversation normally.

2.AUTH

The purpose of the AUTH command is to authenticate the client to the SMTP server. This allows the client to enjoy certain privileges on the server. The AUTH command can contain one of four keywords that provide specifications regarding security levels and login methods: LOGIN, PLAIN, MD5, and CRAM-MD5.

This command is follow by a request for a username and password. When the correct information is provide and the server responds positively, the SMTP session is consider authenticatE.

3. BDAT

The BDAT command can be consider as an extend alternative to the DATA command as it is also a request to transfer email data.

Specifically, the BDAT command is use for the transfer of large MIME (Multipurpose Internet Mail Extensions) messages that can contain various types of data such as audio, video, images, or applications.</p>

4. ETRN

The ETRN or “Extend Turn” command is an extend SMTP command. The purpose of the ETRN command is to allow an SMTP client. A to command a server to send all the mail it may have.

When the command is accept, the server responds with a 250 OK code, at which . A point it begins processing the message queues.