Knowledgebase

When you set up your email account in your email client (Outlook for example), you'll be asked if you want to create a POP3 or IMAP account. POP3 is usually selected as the standard choice and therefore it is most often used.

POP3

POP3 will download the mail you have received on the server, to your PC. It then deletes the mail from the server (this can be changed with a setting). This means that we often can't backup your email, as the email client always downloads and deletes the email, from our server.

IMAP

IMAP is a newer protocol, that reads your email directly on the server. It doesn't delete any content. This also gives you the ability, to create the account on multiple computers, tablets or phones and always see the same content. You'll also be able to use your webmail, no matter where you are. In this case we'll be able to backup your email and this ensures that you won't end up in a situation, where lost/deleted mail, can't be restored.

Our conclusion

You should choose IMAP, when creating a new email account. Especially if you use multiple computers/devices, so they'll always see the same content.

Unfortunately you can't change an existing POP3 account, to IMAP in your email client.  You'll need to create it as a new account in your email client. Don't delete your POP3 account before you've ensured, that you've backed up all of your email. Create the IMAP account side by side, with your existing POP3 account so you can copy your email from the POP3 account to the IMAP account.