Click Digital Products

When dealing with email you may have come across the abbreviations POP3 and IMAP, this article explains what these are and how they are different from each other.

POP3 stands for “Post Office Protocol 3” and IMAP stands for “Internet Message Access Protocol” and both are different email protocols i.e. they are like different languages that can be used by your PC to fetch emails from your email providers server. A server is simply a computer system which in this case is receiving emails and holding onto them until you download them to your PC.

When you use a POP3 protocol it will always download all new emails from the server to you PC, while the IMAP protocol downloads email summaries and will not download the full email until you explicitly select that email.

The POP3 protocol is used when you only download your emails to the same PC, as it downloads all the emails to that PC each time your PC accesses the server, and the emails are then normally deleted from the server. The POP service can therefore be thought of as a "store-and-forward" service. The POP3 protocol is a standard protocol and is built into most popular e-mail products, such as Eudora and Outlook Express.

If you want to access your emails from a number of different computers, such as your home or office PC and your laptop, then you should use the IMAP protocol as the emails remain on the server until you specifically delete them from the server. The IMAP protocol therefore provides the user with more capabilities for retaining e-mail on the server and for organizing these emails in folders on the server. The IMAP protocol can therefore be thought of as a remote file server.

You may have also come across the abbreviation SMTP which stands for “Simple Mail Transfer Protocol” and is a simple protocol for sending and receiving e-mail. However, as it is limited in its ability to queue emails at the receiving end i.e. on your PC, it is usually used with either the POP3 or IMAP protocols. In that situation SMTP is used to send the emails from you PC to the server while POP3 or IMAP is used to fetch the emails from the server.

The above information is useful to understand when for example looking at free email service providers, see our article “Free email service provides.” .