What Is the Difference Between IMAP and POP3?

IMAP and POP3 are both email communication protocols. Before discussing their differences, you can read the full names of these protocols below.

  • IMAP: Internet Message Access Protocol
  • POP3: Post Office Protocol v3

Differences:

  1. Location of Emails:
    • IMAP: Your emails remain on the server, and you don’t need to download them to your device.
    • POP3: Emails are downloaded to your device, such as your phone, computer, or tablet.
  2. Storage
    • IMAP: Since emails are continuously stored on the server, the hosting storage (email storage) space can fill up quickly. This is because, even though a copy of the email may appear on the device, the actual data is stored on the server.
    • POP3: When setting up the application, if the ‘Leave on Server’ option is turned off, the email is deleted from the server as soon as it is downloaded to the device. This allows for freeing up space on the server and easier use of storage. If the ‘Leave on Server’ option is turned on and a retention period is selected, the email remains on the server for the specified period (e.g., 14 days) and is then deleted. However, the important point to note here is that the emails will no longer be on the server, but on your device. If your device or email application malfunctions, the emails may be permanently deleted since the data is no longer stored on the server. Therefore, it is recommended to back up your emails regularly.
  3. Synchronization
    • IMAP: You can access your emails from multiple devices (such as phone, computer, tablet) simultaneously and use them in a synchronized manner. For example, an email you read or delete on your phone will be synchronized with other devices, so it will also appear as read or deleted on your tablet.
    • POP3: There is no automatic synchronization between devices. For example, an email you read on your phone will not be synchronized with your other device, and the email may still appear as unread on that device.
  4. Port Numbers
    • IMAP:
      • Port 143 – Unencrypted port
      • Port 993 – SSL/TLS port
    • POP3:
      • Port 110 – Unencrypted port
        Port 995 – SSL/TLS port