If you have ever set up an email client or app, you will have certainly must have wondered what to use: POP or IMAP. POP3 and IMAP are two different protocols (methods) used to access email.
IMAP is short for Internet Message Access Protocol, while POP translates to Post Office Protocol. In other words, both are email protocols. They allow you to read emails locally using a third party application. Examples of such applications are Outlook, Thunderbird, Eudora, GNUMail, or (Mac) Mail.
IMAP is the better option - and the recommended option - when you need to check your emails from multiple devices, such as a work laptop, a home computer, or a tablet, smartphone, or other mobile device. Tap into your synced (updated) account from any device with IMAP. POP3 downloads email from a server to a single computer, then deletes it from the server. Because your messages get downloaded to a single computer or device and then deleted from the server, it can appear that mail is missing or disappearing from your Inbox if you try to check your mail from a different computer.
The original protocol is POP. It was created in 1984 as a means to download emails from a remote server. IMAP was designed in 1986 to allow remote access to emails stored on a remote server.
Essentially, the main difference of the two protocols is that POP downloads emails from the server for permanent local storage, while IMAP leaves them on the server and just caches (temporarily stores) emails locally.
In other words, IMAP is a form of cloud storage.
How Do They Compare?
The two protocols are best compared by looking at their most basic workflows.
Connect to server.
Retrieve all mail.
Store locally as new mail.
Delete mail from server*.
*The default behavior of POP is to delete mail from the server. However, most POP clients also provide an option to leave a copy of downloaded mail on the server.
Connect to server.
- Fetch user requested content and cache it locally, e.g. list of new mail, message summaries, or content of explicitly selected emails.
- Process user edits, e.g. marking email as read, deleting email, etc.
As you can see, the IMAP workflow is a little more complex than POP. Essentially, folder structures and emails are stored on the server and only copies are kept locally. Typically, these local copies are stored temporarily. However, you can also store them permanently.
What Are the Advantages of POP?
Being the original protocol, POP follows the simplistic idea that only one client requires access to mail on the server and that mails are best stored locally. This leads to the following advantages:
- Mail stored locally, i.e. always accessible, even without internet connection.
- Internet connection needed only for sending and receiving mail.
- Saves server storage space.
- Option to leave copy of mail on server.
- Consolidate multiple email accounts and servers into one inbox.
What Are the Advantages of IMAP?
As mentioned in the introduction, IMAP was created to allow remote access to emails stored on a remote server. The idea was to allow multiple clients or users to manage the same inbox. So whether you log in from your home or your work computer, you will always see the same emails and folder structure since they are stored on the server and all changes you make to local copies are immediately synced to the server.
As a result, IMAP has the following advantages:
- Mail stored on remote server, i.e. accessible from multiple different locations.
- Internet connection needed to access mail.
- Faster overview as only headers are downloaded until content is explicitly requested.
- Mail is automatically backed up if server is managed properly.
- Saves local storage space.
- Option to store mail locally.
What Is the Best Email Protocol for Me?
POP if …
- You want to access your mail from only one single device. That is you use only one computer to check your email (no other devices)
- You need constant access to your email, regardless of internet availability. These mails are stored on the computer that you use
- Your server storage space is limited.
- You wnat to store mails locally on your PC, not on a mail server
IMAP if …
- You want to access your email from multiple different devices.
- You have a reliable and constant internet connection.
- You want to receive a quick overview of new emails or emails on the server since they are store on the server so you can see it from any device.
- Your local storage space is limited.
- You are worried about backing up.
Whenever in doubt, go with IMAP. It’s the more modern protocol, allows more flexibility, emails are automatically backed up on the server, and available server space are quite generous that you don't have o worry about space. You can still store important emails locally.