Understanding IMAP is simple:

When you check your email, your email client connects to a receiving server. In many cases, this server is an IMAP server, and it synchronizes the email in your account with that on the server.

So, let’s give IMAP a round of applause, shall we?

But before we shower IMAP with praise, let’s answer a few crucial questions about it first.

What is IMAP, and how does it work? ‍

IMAP’s primary function is to retrieve emails from receiving servers.

Instead of transferring the email, it keeps it on its own IMAP server, which becomes accessible to you if you’ve configured the IMAP server in your email client or app.

All messages and even folder structures get synced with IMAP. That means that if you make changes to them in your email client or app, these changes will also be applied to the emails on the IMAP server.

The cool thing is that you can connect with multiple devices and email clients, and your email account will still sync perfectly, thanks to IMAP.

Here’s a slightly more technical explanation:

  1. ➡️ The email client (Gmail, Outlook, etc.) connects to the IMAP server through a secure connection
  2. ➡️ Once connected, the mailbox on the IMAP server and the one in the email client synchronize. Any changes made are reflected on both the email client and the server.
  3. ➡️ On reading an email message, the email client retrieves the message to display it to the user. The email won’t be downloaded unless the user specifically opts to do so.
  4. ➡️ Users can create and delete email folders, which will all be synchronized
  5. ➡️ Users can access their mailbox offline. On reconnection, the email client synchronizes the changes with the IMAP server.

How does IMAP differ from POP3?

Where IMAP retrieves and synchronizes emails, POP3 retrieves them and then deletes them from the server.

In other words, with POP3, there’s no synchronization.

POP3 was used a lot for offline desktop email clients but with the arrival of IMAP with its distinct synchronization advantage, POP3 usage has been in decline.

This lack of synchronization with POP3 can lead to data loss or inconsistencies across devices.

Partner in crime

When it comes to receiving email and synchronizing mailboxes, IMAP will be the preferred choice in the foreseeable future.

For sending email, another protocol is the leading player in town: SMTP.

To get the lowdown on the differences between IMAP and SMTP and how they work together, read: IMAP vs SMTP – Email protocols explained in simple terms.