Difference between POP3 and IMAP email protocol

POP3 and IMAP email protocols are used for retrieving email from an email server. For example, if you’re using an email client, such as Microsoft Outlook, you would configure Outlook with either POP3 or IMAP to retrieve your email on a computer. You can also use these protocols on your tablet or smartphone to retrieve your email. But, what are the differences and which is better?

POP3 protocol

POP3 stands for Post Office Protocol 3. POP3 is the simpler of the two protocols because the only thing that POP3 does is download the email from a mail server to your device. It only downloads what’s in your inbox folder, which is where your email is.

It doesn’t download any other folders or their contents, like your sent items, your drafts, your deleted emails and so. Also, it doesn’t do any kind of synchronization. For example, let’s say that you have two computers that are configured to retrieve the same email account. By default, when you’re using POP3, the email will be deleted on the mail server once it’s downloaded to a device. No copy of the email is kept on the server. This means that when a new email comes in to the mail server, if one computer checks the mail server before other computer, the first computer will receive the email. All other configured computers will not because the email has already been downloaded and no copy of the email is kept on the server. However, most email clients will have a setting that you can check to leave a copy on the server. If this is the case, all of your devices can retrieve the email.

IMAP protocol

IMAP stands for Internet Message Access Protocol. IMAP is also used for retrieving email, but in a different way. IMAP allows you to view your email that’s on the server from multiple devices. The email is kept on the server and it caches local copies of the email on to all of your devices. It also synchronizes all of your folders and everything that’s in them. It syncs your inbox, sent items, deleted items, drafts and any custom folders that you may have created.

When you view your email on your computer, tablet, or smartphone, your email would be exactly the same because everything is synchronized. For example, if you have two computers configured for access to the same email account using IMAP, all the email and folders would be exactly the same between these two computers. If you delete an email on one computer, the email will be deleted on the mail server and then be deleted on the other computer also.

If any new emails come in, the email first goes to the mail server, and then, as the configured computers sync with the mail server, the new email will appear on all computers. If you make a custom folder with custom name, because of IMAP the folder and all of its contents will be added and synced to the server and any other configured computer or device like tablet or smartphone.

What to use, POP3 or IMAP?

POP3 only downloads the contents of your inbox folder, it doesn’t do any email or folder syncing. IMAP syncs everything with all of your devices. Both POP3 and IMAP are configured in your email client in the incoming server settings. Which protocol to use depends on your situation.

Advantages Disadvantages
POP3 POP3 is good if you’re only going to retrieve your email from one device. The advantage of using POP3 is that since the email is downloaded to your device, you can view your downloaded email even if you don’t have an internet connection. The only time that you need an Internet connection with POP3 is when you’re receiving new email or sending email. Another advantage of POP3 is that it saves storage space on the mail server because the emails are deleted when they are downloaded to a device. Disadvantage of POP3 is that since the emails are removed from the server and downloaded to your device, you would need a plan to backup your emails in case your device crashes or is lost. Another disadvantage is that your device has a better chance of being infected with viruses since the emails are fully downloaded.
IMAP IMAP is good when you’re going to retrieve your email from multiple devices. All emails are stored on the mail server, so whether you’re accessing your email using an email client or webmail, you’ll be able to see all your email including your sent items, drafts, deleted items, and any custom folders. Also all the email and all folders are all synchronized so every device that you have will see the exact same thing. Disadvantage of IMAP is that you will not be able to view your emails without an Internet connection. This is because IMAP only caches local copies of the email on your device and doesn’t download them. However some email clients will give you an option that you can check to have IMAP download the emails to your device instead of just cashing them.