What is SMTP?

SMTP is a short for Simple Mail Transfer Protocol and it is used to transfer e-mail messages between computers. It is a text based protocol and in this, message text is specified along with the recipients of the message. Simple Mail Transfer Protocol is a 'push' protocol and it cannot be used to 'pull' the messages from the server.

A procedure of queries and responses is used to send the message between the client and the server. An end user's e-mail client or the relaying server's Mail Transport Agents can act as an SMTP client which is used to initiate a TCP connection to the port 25 of the server. SMTP is used to send the message from the mail client to the mail server and an e-mail client using the POP or IMAP is used to retrieve the message from the server.

SMTP Functions
An SMTP server performs the following two functions :
1. It verifies the configuration and grants the permission to a computer that is making an attempt to send a message. It sends the message to the specified destination and tracks it to see whether it's delivered successfully or not. If it's not delivered successfully then an error message is send to the sender.

2. There's one limitation to SMTP and it's the inability to authenticate the senders and this results in e-mail spamming. The enhanced version of SMTP also exists and its called as Extended SMTP (ESMTP). ESMTP is used to send the e-mails that include graphics and other attachments.

  • 0 Users Found This Useful
Was this answer helpful?

Related Articles

iPhone Email Setup

Go to the Main Menu and select Settings. Scroll down and select Mail. Select Add...

Does AOL block port 25?

AOL has recently began to block port 25. What does this mean for you, our customers?...

Login to Webmail

  If your website is hosted through us, this is where you can log in to your e-mail. To...

Email setup in Outlook

Open Outlook, and on the Tools menu, click Accounts.   In the Internet Accounts...

Best practices to help prevent spam

  Follow these guidelines to help lower your risk of getting junk e-mail....