SMTP, IMAP, and POP3

SMTP, IMAP, and POP3 are the three email protocols. These protocols are used by web servers to ensure a ‘safe’ (i.e., lossless) email transfer.

SMTP

SMTP is the Simple Mail Transfer Protocol that is also known as a push protocol because it is used to send emails. SMTP is used by mail clients (e.g., Gmail or Yahoo) to send emails. A few features of SMTP are:

• Mail Relaying
• Mail Forwarding
• Mail Gatewaying
• Address Debugging
• Mailing List Expansion
• Turning

IMAP and POP3

Internet Access Message Protocol (IMAP) and Post Office Protocol version 3 (POP3) are both pull type protocols that are used by mail clients to retrieve emails.

The question arises that if IMAP and POP3 are both used for receiving emails, what is the difference between the two?

IMAP vs. POP3

After downloading an email from a server to a single computer, POP3 deletes that email from the mail server.

Meanwhile, IMAP stores the message on the server and synchronizes the same email across multiple devices (i.e., mobile, tablet,​ and computer). This protocol is much safer than POP3.