Internet Message Access Protocol (IMAP): Definition

Internet Messaging Access Protocol (IMAP) is an internet standard that describes a protocol for retrieving messages from an email server. When you use IMAP, you can synchronize applications on multiple computers accessing the same email account, to show the same state and messages.

What is Internet Message Access Protocol (IMAP)?

Internet Message Access Protocol (IMAP) is a protocol for accessing email or bulletin board messages from a (possibly shared) mail server or service. IMAP allows a client e-mail program to access remote message stores as if they were local. Email stored on an IMAP server can be manipulated from a workstation at the office, a desktop computer at home, or a notebook computer while traveling, without requiring the transfer of messages or files back and forth between these computers.

Why should you care about IMAP?

If you use Gmail, Yahoo Mail, or another webmail service with IMAP support, you should care about IMAP because it will help you save time accessing your email on multiple devices and moving messages between folders.

How Internet Message Access Protocol works

Now that you know some of the histories of the protocol, we’re going to interactively introduce you to the nuts and bolts of how it works. We’re going to connect to an email account, list all of the available folders in the mailbox, and download a message. Along the way, we’ll identify and explain the relevant parts of the protocol needed to understand what is happening.

You’ll be able to follow along as we walk through the protocol, as long as you have access to a terminal, the OpenSSL command-line utility, and an email account that supports IMAP (including Gmail).

Advantages of IMAP

• It offers synchronization across all the maintained sessions by the user.
• It provides security over POP3 protocol as the email only exists on the IMAP server.
• Users have remote access to all the contents.
• It offers easy migration between the devices as it is synchronized by a centralized server.
• There is no need to physically allocate any storage to save contents.

Disadvantages of IMAP

• Internet Message Access Protocol is complex to maintain.
• Emails of the user are only available when there is an internet connection.
• It is slower to load messages.
• Some emails don’t support IMAP which makes it difficult to manage.
• Many browser-based solutions are unavailable due to not support of IMAP.

Summary

Through following along in this post, you’ve learned Internet Message Access Protocol (IMAP), an open protocol for accessing and manipulating remote mailboxes. We’ve connected to an IMAP server, logged in to our email account, listed folders on the remote server, and downloaded message data. This is exactly what happens under the hood in email apps as you browse your mailbox. We also learned that because of how IMAP developed over the years, disconnected syncing is fairly complicated for clients to implement – which is why we built our delta API to simplify the process.