The difference between POP3 and IMAP

POP3 (Post Office Protocol)

POP, or Post Office Protocol, is a way of retrieving email information from a remote email server. Computers a decade ago only had limited, low bandwidth access to remote computers, so engineers created POP in an effort to create a dead simple way to download copies of emails for offline reading on a personal computer, then POP3 removes those mails from the remote server.

Since POP3 creates local copies of emails and deletes the originals from the server, the emails are tied to that specific device or computer, and cannot be accessed via any webmail or any separate client on other computers. Although this can be changed in most mail clients by selecting an option of leaving a copy of the message on server.

While POP3 is based on a model of offline email, there’s no reason to call it obsolete technology, as it does have its uses and is a realiable transport medium for emails.

IMAP (Internet Message Access Protocol

IMAP was created in 1986, but seems to suit the modern day world of always-on internet connectivity quite well. The idea was keep users from having to be tied to a single email client, giving them the ability to read their emails as if they were “in the cloud.”

Compared to POP3, IMAP allows users to log into many different email clients or webmail interfaces and view the same emails, because the emails are kept on remote email servers until the user deletes them. In a world where we now check our email on web interfaces, email clients, and on mobile phones, IMAP has become extremely popular. It isn’t without its problems, though.

Because IMAP stores emails on a remote mail server, you’ll be limited by the size of your mailbox quota. If you have huge numbers of emails you want to keep, you could run into problems sending and receiving mail when your box is full. Some users sidestep this problem by making local archived copies of emails using their email client, and then deleting them from the remote server.

Which Do I Use to Set Up My Email?

Depending on your style of communicating and how you prefer to access your email, below are a couple of pointers to choose between IMAP and POP3:

• If you use check your email from a lot of devices, phones, or computers, set up your email clients to use IMAP.
• If you use mostly webmail and want your phone or iPad to sync with your webmail, use IMAP, as well.
• If you’re using one email client on one dedicated machine (say, in your office), you might be fine with POP3.
• If you have a huge history of email, you may want to use POP3 to keep from running out of space on the remote email server.