Key Differences between SMTP, IMAP, and POP3

SMTP, IMAP, and POP3 have customized TCP/IP protocols that are utilized for receiving and sending emails. It is crucial, as tech experts, to comprehend these protocols to fulfill the application needs.

In this post, we will be looking at the meaning of these three protocols and the differences between the three. So let’s get started.

Simple Mail Transfer Protocol (SMTP) – What is it?

SMTP is a popular TCP/IP protocol for transmitting emails. Users primarily utilize SMTP to transmit emails to computer servers or communication between multiple servers.

There are two kinds of SMTP servers, which are, Receivers and Relays. Receivers transmit e-mails to the mailbox after receiving them from the Relay, while Relay approves emails from the clients and directs them to the end recipients.

Internet Message Access Protocol (IMAP) – What is it?

IMAP is a protocol for getting mail from the server. IMAP maintains the email on the server after delivery since it enables concurrent access to emails from various places. Additionally, until the receiver opens the email, the complete file is not downloaded.

The IMAP protocol, one of the widely popular protocols used for receiving emails, is now in use in its fourth version.

Post Office Protocol, Version 3 (POP3) – What is it?

A more convenient and adaptable approach to accessing a mailbox is via the POP3 (the Post Office Protocol). The most prevalent version of this solution is the 3rd version, which is well-liked by users because of its minimal need for Internet connectivity. POP3 allows you to access emails even if you are not online because it sends emails from the server to the user.

Key Differences between SMTP, IMAP, POP3


  • IMAP is utilized for receiving emails while SMTP is utilized for sending.
  • SMTP transfers data between servers, while IMAP facilitates communication between the user and the server.
  • IMAP clients can arrange their emails on the server, but SMTP users can arrange their emails only on the client storage.


  • IMAP displays the email header before transferring and downloading the email, but POP3 downloads every email at once.
  • POP3 takes emails from servers, removes them, and then does it again. IMAP syncs the email across many devices so that it can be accessed via various channels after being stored on the server.
  • Organizing the server mailbox is not possible with POPs, but it is possible with IMAP.
  • IMAP maintains several copies of the email to facilitate recovery, while POP3 does not.


  • POP3 is a pop protocol whereas SMTP is a push protocol.
  • POP3 gets and arranges emails from the recipient’s server and downloads them to the computer, whereas SMTP transfers the email to recipient’s mailbox to the sender’s device.
  • SMTP connects the mail servers of the sender, while POP3 connects to the mail server of the recipient.

In this post, we looked at the definition of SMTP, POP3, and IMAP along with the crucial difference. All three of them are popularly used for email transmitting purposes.

We hope you found this post useful. For more assistance, you can always get in touch with our customer support team who are available around the clock.

Also Read: How to Change SMTP Server IP (Exim IP) on WHM Server?