If you have had to look around for email services, you have probably seen the abbreviations POP3 and IMAP come up several times in your searching. Today we are taking a broad look at each protocol and explaining what they do and how they relate.
Starting with POP3
POP3 stands for Post Office Protocol 3. It is the third version of the Post Office Protocol and it works very much like the name implies: like a post office. If you were to pick up your mail at a post office, you would then be the only person with that email. In the same way, when a mail server is using POP3, they do not store a copy of the email on the server. As soon as you have retrieved the mail and downloaded it onto your local machine, aka it is received in your inbox, that is it.
Do not panic yet though because there are ways to configure POP3 to store mails on the server as well, though usually only for a limited time.
This can also be seen as an advantage. That means that you have one less server with data on it at any given time! That decreases the risk and can improve security. POP3 is a great protocol because it is very simple and it does not have many points of failure. It will just keep on running!
IMAP stands for Internet Message Access Protocol. The major difference between POP3 and IMAP is, you guessed it, the storage of your email messages. POP3 is the one that has no messages stored on the server once they are retrieved by the client. IMAP on the other hand, keeps all of the messages on the server and they are never downloaded to the client. This can make for a lighter client impact as far as the resources used for email services.
Because messages are preserved on the mail server, they can be viewed by the user on any device that they authenticate to. This can give greater flexibility to users who use their email on multiple devices. As you can imagine with the rise of smartphones, IMAP has increased in usage significantly with more users on mobile devices and desktops for their email use.