POP vs IMAP

Overview

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What is an Email Protocol?

An email protocol is a set of rules that allows servers of different makes and operating systems to talk to each other for the purpose of transferring emails to and from one other. Protocols are used extensively in networking, but there are three common protocols that are used for email.

• POP or POP3 – Post Office Protocol (version 3)
• IMAP – Internet Message Access Protocol
• SMTP – Simple Mail Transfer Protocol

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Incoming Email Protocols

There are two protocols commonly used for incoming mail, POP and IMAP. What protocol is used is determined when you set up the mailbox in your mail client, not by the server. You can use either protocol on most devices, although some older software or devices may only support POP. You can access the same mailbox using both protocols, you do not have to choose one per mailbox.

POP3

POP, or Post Office Protocol, retrieves messages from the server and stores them on your local storage. By default, a POP account will check for new mail in your Inbox, download the new messages, and then remove the email from the server. Most modern email clients will allow you to leave a copy on the server, but you may need to find the option the mail client settings. However, this can cause disk usage issues as deleting mail from the mail client POP account does not remove it from the server, causing email to build up on the server over time.

Advantages

The advantage to checking emails with POP is that you aren’t limited by the space allocated to that mailbox on the server side, since the messages are typically removed from the server after they are downloaded.

Disadvantages

The main disadvantage of checking email with POP is that you will only have an archive of your messages and folders on a single device. If you have multiple devices set up as POP, only the first device that sees the email will get to download a copy of it, as the email will then be removed from the server before the other devices see it. This is why if you check your emails from multiple computers or devices (such as an iPhone), then you will want to setup your email with IMAP. You can set your POP account to leave a copy on the server, but you will need to monitor your disk usage on the server to ensure old mail are getting deleted from the server.

Also, a POP account will not have access to other folders in your mailbox. If you use email folders, you will want to use IMAP.

IMAP

An IMAP email account stores messages on the mail server and syncs between all other IMAP accounts connected. It also allows you to create folders and access the folders from any location.

Advantages

The advantage to checking emails with IMAP is that you have a central storage for all of your mail and your archives can be checked from any computer with an internet connection. This is beneficial if you are checking from multiple computers or devices (like an iPhone). This means that any mail read, moved, or deleted on one device is reflected on all other devices. This makes managing your account from multiple locations easier. You also will be able to access all the folders set up on your mailbox (called IMAP folders for this reason).

Disadvantages

The main disadvantage of checking email with IMAP is that you are limited to the allocated storage space on the server for that specific email account. If you are checking email from a single computer most of the time and/or regularly receive large attachments, you will want to consider using a POP account instead.

Conclusion

You can use POP if you only ever check your emails from one device and don’t use mailbox folders. Other than that, you should be using IMAP. You can get POP to work like an IMAP account, but unless you are comfortable with digging into the settings on your devices, you probably should use IMAP.

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Outgoing Email Protocols

Deciding what outgoing protocol to use is easy. There is only one, SMTP (think Send Mail To People). The main advantage that SMTP has over other outgoing protocols is that it exists.

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Bonus Pro Tip

One option to make use of both POP and IMAP is to set up most of your devices as IMAP, but set up one device (preferable a desktop) as POP, and set it to leave a copy of mail on the server and never delete. This will allow you to manage your email from any device and move mail into folders, but the one POP account will be creating a copy of all your mail, so you can use if for backup purposes. This could be helpful if you need to keep emails long term. You can delete them from the server, but keep a copy of it locally.

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