POP vs. IMAP – the eternal battle for protocol supremacy

Long story short, POP and IMAP are what is know as email protocols.

In computing, a protocol is a set of rules that are used to assist with communication between different types of computers. Internet standard protocols are used extensively in computing and especially networking.

Without the use of protocols, computers running different Operating Systems (OS) would not be able to communicate with each other effectively. Most mail servers are Linux based, but most end users are using Windows or Apple devices. Using an email protocol, you are able to check your mail on whatever device you like, even though they are built on a different OS.

Both POP and IMAP email protocols provide the tools necessary for this communication to take place, but how they achieve this is quite different. The main difference between the two protocols is how they access and manage your emails.

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POP, or Post Office Protocol, is the older of the two common email protocols. The current version of POP is POP3. You will sometimes see it mentioned as either POP or POP3.

When a POP client connects to your mail server, it will search your inbox for new emails. Once it finds new emails, it will download them (or “pop” them off the server) to your local machine (your computer, laptop or phone), and then delete the mail from the server. While modern mail clients can modify this behavior, this is the default process of a POP email client.

One of the main advantages of a POP account is that you do not need to worry about your email mailbox getting full with emails, as the emails are downloaded and deleted from the server. All of your email are stored on your local computer and you can even browse and read your email offline.

You can leave your emails in your POP client and store them long term, without the fear of them being accidentally deleted from the server.

If you only have one computer that you check your email on, then a POP account may work great for you.

While “popping” your email off of your mail server is great for keeping your server mailbox empty, there are setbacks to this method.

First, if you use more then one email client, say you have your email account set up on your home and business computers, as well as your phone so you can check your email on the go, POP can cause issues.

Essentially what happens is, when an email is delivered to your inbox, the next mail client (lets say your work computer) that checks for new mail will see it and download it, and then remove it from the server. Now, when your other devices check for mail, they will not see that email, but maybe you received another since the first was downloaded. That device will download that email. Now, you have different email on each device.

Another downside of POP is that the email client will only check the inbox, and not any other folders. Because of this, many of the benefits of using email folders cannot be used with a POP account, such as filters and Email Plus Addressing.

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IMAP, or Internet Message Access Protocol, it a more modern email protocol. It is sometimes referred to as IMAP4, as it is currently on version 4.

The main difference with IMAP is that instead of “popping” the mail off of your mail server, your IMAP client syncs the emails with the server. Any mail that is on the server, is copied over, and any mail that was moved or deleted on the device is moved or deleted on the server.

The main advantage of IMAP over POP is the reason it was created in the first place. This is the ability to manage your emails using several mail clients on different devices. Because each device syncs with the mail server, and new mail, deleted or moved mail is reflected on each device. So, if you received a new mail while on your computer, you can read it later on your phone. Then, once on your work laptop, you can decide to delete it or move it into a folder.

Speaking of folders (often referred to as IMAP folders), they are another huge advantage of IMAP clients. As explained earlier, a POP client only checks for new email in the inbox. But, you may want to filter your incoming mail into folders to keep them organized. If the mail is filtered into folders on the server, then a POP client will not download them. An IMAP client will sync all of your folders as well, although most clients will allow you to choose what folders to sync.

IMAP also allows you to take advantage of Email Plus Addressing that can help you keep your email sorted.

The only disadvantage of the IMAP email protocol is that, because all of the mail is stored on your mail server, you do need to maintain your disk space on your email account. If you never delete emails, your mailbox on the server will eventually fill up. Once your mailbox is full, you will not be able to receive new emails. Of course, most email clients allow you to archive email to your local machine, so this can help you keep your mailbox clear.

If you use IMAP on several devices, you will also need to be careful, as deleting your emails from one device will delete it from all devices, and the mail server. Once deleted, the email may be gone forever.

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Now that we know what the difference is between the two email protocols, which one should you use?

IMAP! Thanks for reading my article.

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Okay, let me explain why you should use IMAP.

If you check your email on several devices, or if you use folders extensively, then you will what to use the IMAP email protocol. These are two common use cases for most modern email users that IMAP just does better.

While most modern mail clients can add features to a POP account that will help it preform like an IMAP account, such as the ability to leave a copy of the email on the server, in most cases, you will need to dig through the settings on the mail client to enable these features. Even with these options enabled, there is nothing that a POP account can do that an IMAP account cannot.

One good use of a POP client is for archiving your emails. If you need to keep all of your emails, then IMAP can become an issue as your mail server fills up. What you can do to mitigate this is to set up one computer (one that is powered on most of the time) with at POP client, set to leave a copy of the email on the server, definitely. Then, you can set up all of your other devices as IMAP accounts. When a new mail arrives, the POP account will make a copy of the email and store it locally, while you are free to manage and possibly delete it on your IMAP devices. However, if you have filters set up on the server, this method will not catch emails sent to folders other then the inbox.

Another small, but relevant advantage of IMAP is that if you need to delete your mail client from a device, you do not need to worry about losing emails. If you delete a POP account, any mail that is on that device, but not on the server will be deleted as well. Where an IMAP client only syncs with the mail server, deleting an IMAP client has no effect on the server.

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