POP3 vs IMAP

What are they?
What is the difference between the two?
Which one should I use?
Conclusion

What are they?

POP3 and IMAP are communication methods that email software uses to receive email.

POP3, which stands for Post Office Protocol 3, is the standard way that email software will receive email from a mail server.

IMAP, which stands for Internet Message Access Protocol, is much newer than POP3 and is used by email software to view mail without downloading it.

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What is the difference between the two?

If you configure your email software or mobile device to connect to your mailbox on our mail server (mail.demon.co.uk) using POP3, the contents of your mailbox will be downloaded to your computer or mobile device for local storage. The mail will then only exist on your computer or mobile device and will not be available to download on another computer or mobile device, unless you have configured your email software to leave a copy of messages on the server.

If you configure your email software or mobile device to connect to your mailbox on our mail server using IMAP, your computer or mobile device will simply connect to your mailbox and display the contents of the mailbox to you without actually downloading the content for local storage (please note – some email software can be configured to keep a local copy of your mail while using IMAP). This has the benefit of allowing you to manage your mailbox from multiple computers and/or mobile devices, all of which will be able to see the same content.

If you think about your mailbox on our mail server as a postbox full of letters and your email software and/or mobile devices as postmen:

  • When using POP3, a postman would visit the postbox, empty the contents and take it away with him.  If a second postman then arrived, he would only have access to the letters that had been placed into the postbox since the first visit.
  • When using IMAP, a postman would visit the postbox and have a look at the letters while he is there, but leave the letters in the postbox when he departs.  If a second postman arrived, he would do the same and still be able to see all of the letters placed into the postbox.

However, it is worth noting that mail is only kept on our server for 30 days and so just using IMAP can result in you losing emails that you had wanted to keep.

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Which one should I use?

It very much depends on how you access and manage your email.

If you want to be able to look at your mail from multiple locations, computers and/or mobile devices, it is usually best to use POP3 on your main computer, with the setting to leave a copy of messages on the server enabled, and IMAP on all other devices.  IMAP will allow you to manage your mailbox on our mail server from the various locations, computers and/or mobile devices while the mailbox content itself stays on our server, and your main computer will have a locally stored copy of your emails, which will be particularly useful for emails older than 30 days. If you were to use POP3 on all devices, with the setting to leave a copy of messages on the server enabled, you are basically creating multiple versions of your mailbox and any changes you make, such as deleting emails, creating sub-folders, etc, would need to be replicated at each location, computer and/or mobile device.

If you are just going to be using one computer, POP3 would be the best option. This provides a simple way of you being able to download all of your mail to one location, which can be managed by you. The mailbox on our mail server would always be empty or at least close to it as a result.

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Conclusion

If in doubt, use POP3 on your main computer, with the setting to leave a copy of messages on the server enabled, and IMAP on your other devices, which gives you the ability to manage your mail from a computer or mobile device while still giving you the peace of mind that there is a backup of your emails on our mail server and your main computer. However, if you are only accessing your mail from one place and need to keep all your mail locally, POP3 may be a better option.

If you need help configuring your email software to send and receive mail, please refer to our configuration guides, which can be found here.

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