My Emails Disappeared, Why It Happens With IMAP and How POP3 Protects You

My emails disappeared? If your account is set up with IMAP, one hack, one wrong deletion on your phone or one problem on the server is enough for them to disappear everywhere at once. Most internet users now have at least one email address, and for businesses, email is among their most important data.

For an email address to work, two servers are needed, or two services on the same server. One handles outgoing mail (SMTP) and the other handles incoming mail (POP3 or IMAP). So there are two ways to receive your email, POP3 and IMAP, and both are protocols your computer uses to talk to the mail server. That choice decides whether you will always have your own copy of your mail.

What is POP3 and how it keeps email on your computer

POP3 (Post Office Protocol 3, because it is the third version) is the protocol that downloads your emails to your computer, so you keep your own archive. It is the evolution of the first POP protocol, created in 1984. Back then hard disks were only a few MB, so servers could not hold many emails, and users had to download them locally every day to free up space on the server.

Email apps that use POP3 connect to the mail server, retrieve all messages, store them on your computer or device as new messages, delete them from the server and finally disconnect. The protocol is still widely used today, and there is no replacement in sight.

Its main advantage is that it keeps a local archive of your emails that you control. Whatever happens to the server, the provider or your account, the mail you have already downloaded stays on your computer.

What is IMAP and how it works

IMAP is the protocol that keeps all your emails on the mail server, the so-called IMAP server, and syncs them with all your devices. IMAP was created in 1986, because developers at the time were not satisfied with POP and wanted access to their email from other devices, at any time.

Unlike POP, IMAP offers two-way communication between the mail server and your email apps. That means actions you take on one side, for example moving an email to a folder on your smartphone, appear immediately and automatically on every other device. IMAP keeps emails on the server, does not delete them and gives synchronised access from many devices.

That is its big advantage, and also its big risk. With IMAP your mail effectively exists in just one place, the server, and your devices simply show what is there.

Difference between POP3 and IMAP

The difference between POP3 and IMAP is where your mail lives. With POP3 emails are downloaded and kept on your computer, while with IMAP they stay on the server and your devices simply sync them. So POP3 gives you your own archive and a mailbox that does not fill up, but harder access from many devices. IMAP gives you the same emails everywhere, but every change, and every deletion, reaches all your devices at once. You will find the full comparison table in the difference between POP3 and IMAP in our knowledge base.

Risks of IMAP for business email

The risks of IMAP all come from the same point: your mail lives only on the server, and whatever changes there changes everywhere. In practice, that means four scenarios where everything can be lost at once.

A hacked account. Anyone who finds your password has your whole email history in front of them, with personal data, bank details and passwords that were sent to you. They can read it, forward it to others or delete it all, and with IMAP the deletion reaches your computer, phone and tablet immediately. See how to create a strong password and enable two-step verification. How your password ends up in their hands is explained in what malware is and how to protect yourself. It often starts with email scams that ask for your password.

A wrong deletion on one device. One "Delete all" on your phone, a child playing with the tablet or a misconfigured app, and the emails disappear from every device at once. With IMAP there is no "my own copy", there is only what the server has.

A problem with the server or the provider. A failure, a mistake in managing the server or a provider that shuts down affects all your email at once. We take a backup every 2 hours with 24 restore points, which includes email, and you can restore it yourself from cPanel. But a server's backups cover a specific period and are controlled by the provider, while you keep your local archive for as long as you want.

An account you can no longer reach. If the domain expires, the hosting plan is not renewed or the employee who had the password leaves the company, with IMAP you lose access to the mail together with the account. With POP3 the emails already downloaded stay on the computer.

Email mailbox full, what to do

An email mailbox gets full usually because the account is on IMAP and messages pile up on the server without ever being deleted. Mailbox space on hosting plans is limited, and it also counts towards the total space of your plan, together with the website and databases.

If it fills up, you will not be able to receive new emails, with whatever consequences that may have for your business, until you make room by deleting old ones. The sender gets a message back saying the email was not delivered, and may never tell you. With POP3, emails are downloaded to your computer and the mailbox does not fill up. If you still need more space, see how to change a mailbox quota in cPanel.

IMAP or POP3 account on your phone

An IMAP account on your phone is the easiest way to see your email everywhere, but you do not have to give up your local copy for that. The downside of POP3 is that once you download emails locally, you cannot easily see them from another device.

The answer is one setting. In the email app on your computer you choose POP3 and enable the option "Leave a copy of messages on the server" for a number of days, for example 14. That way your computer keeps the permanent archive, while on your phone or in webmail you see the recent emails of the last few days. It is not recommended, though, to have the same account on POP3 and IMAP at the same time, because it can create duplicate messages or changes that do not sync. The settings for each app are in the email client settings, and for iPhone in setting up email on iPhone and iPad.

Back up emails in Outlook and Thunderbird

Backing up emails in Outlook and Thunderbird is needed when you work with POP3, because your archive now lives on your computer. If your disk fails, your emails will be lost together with the rest of your data, so the local archive needs its own copy too.

In Outlook, POP3 emails are stored in a .pst file, and Microsoft describes how to export it to a .pst file. In Thunderbird everything is in the profile folder, and Mozilla explains how to move or copy it. Copy that file or folder regularly to an external disk or cloud storage. That way your mail exists in three places: on your computer, in your copy and, for the days you leave it there, on the server.

Use POP3 if you can. I recommend it that clearly. Even if your email is on Gmail or Outlook.com, where space is large, the risk from a hack or a wrong deletion is the same, so keep a local copy of your important mail there too.