But do you know what are they meant by POP3, IMAP & SMTP? In this article I will try to describe what the three terms above. POP3 (Post Office Protocol version 3) is a protocol used to retrieve electronic mail (email) from the email server. POP3 protocol was created because of the design of the electronic mail system that requires the server to accommodate email for a while until it’s taken by an eligible recipient.
IMAP (Internet Message Access Protocol) is a standard protocol for accessing / retrieving e-mail from the server. IMAP allows users to choose e-mail message that he will take, make a folder on the server, search for specific e-mail messages, even deleted e-mail messages on server. This ability is much better than POP (Post Office Protocol) which only allows to retrieve/ download all the messages without exception.
SMTP (Simple Mail Transfer Protocol) is a commonly used protocol for sending electronic mail on the Internet. This protocol is used to transmit data from computer sending email to the recipient mail server.
Look at table below for the comparison between POP3 and IMAP