What is IMAP / POP and which should I use?
Summary:
If you want your emails to remain
synchronised across
multiple devices then we recommend using
IMAP. If you are concerned about
Disk Space Usage and want to delete your emails from the server (while retaining a copy on just one device), use
POP.
For more information about these two options, read on!
IMAP vs POP
IMAP (Internet Message Access Protocol) and POP (Post Office Protocol) are used in email communication. Note that these protocols dictate how email clients behave when connecting to our server.
IMAP
is particularly useful for mailboxes which are intended to be accessed by more than one device. The messages are stored on the server until explicitly deleted. This allows different people on different computers using different email clients to access the same list of messages. If you delete a message on a device which is using IMAP, it will synchronise with the server and delete that email from the server, which will in turn remove that email from other devices.
In some email clients it's possible to move emails to local folders that don't get synced across devices, but these folders also wouldn't get saved on the server.
As an example, you may have emails on a work computer, but also want to access your emails from a home computer and a phone. In this case, IMAP would be ideal for you.
POP downloads emails to your device and removes them from the server to save space. In a similar manner to a letterbox, the server holds your letters until your computer downloads them. They are then removed from the server. POP does have an option to keep a copy of the emails on the server (usually for 7-30 days) before deleting, but this is not enabled by default.
Generally we'd recommend against using POP (see below), but it's more attractive in circumstances where you have very large amounts of emails and only one computer that will be connecting to an email account.
Email Recovery
If your computer uses IMAP for emails and the device breaks, you can simply log into your account on another device and your emails will re-download. You'll only lose access to any folders you specifically set up not to sync to the server. If you accidentally delete emails, you can use our guide on restoring emails from our R1Soft backups.
If your computer uses POP for emails and the device breaks, you will have lost all emails except for those that are still on the server (if any). Using a POP setup, no Sent items are stored on the server, so these would be lost as well. If you accidentally delete emails, you could possibly restore them using our backups. However the emails need to have been on the server for more than 8 hours during the past 7 days (so our backups could run and retain a copy).
In summary, it's a lot harder to get back deleted emails when using POP, as the emails are stored on a client's device instead of our server.
Interactions
As mentioned, these protocols dictate how email clients behave when connecting to our server. This means you can use different protocols for different email accounts - admin@yourdomain.net.au could use IMAP, while error_log@yourdomain.net.au could have a POP setup to make sure error emails aren't stored on the server.
If you had an email account that a POP email client and an IMAP email client were using, you would find that emails would disappear off the device using IMAP. This is because the POP client downloads the emails and deletes them off the server, while the IMAP client syncs itself with the server.
Similarly, if you had two POP email clients logging into the same email account, half your emails would go to one POP client and the other half would go to the other POP client. Neither would get the full amount of emails, as the POP protocol deletes the emails from the server once it downloads them. You can make this work by specifying that emails stay on the server for X days before deletion, but if one email client is ever offline for more than that amount of days it will miss emails.
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