When it comes to accessing your email, POP3 vs. IMAP isn’t just a matter of preference. POP3 is old, outdated, and not suitable for the modern world. IMAP is the one you should be using.

Exchange is also fine — if you have some sort of work email account and it uses Exchange, you’re good. Exchange works similarly to IMAP, but is a proprietary Microsoft protocol that isn’t available everywhere.

When This Matters

RELATED: Email: What’s the Difference Between POP3, IMAP, and Exchange?

POP3 vs. IMAP is a choice you make when you use an email client to access your mail. That email client is often a desktop program on Windows, Mac, or Linux, but it can also be a smartphone or tablet app.

If you access your email via a web interface or an official mobile app — like accessing Gmail with the Gmail app on Android or iOS or accessing Microsoft’s Outlook mail from outlook.com — you don’t have to worry about this. It will just work.

Microsoft refused to support POP3 with Windows 8’s included Mail app, requiring workarounds to access a POP3 email account. While this was controversial, they’re at least pushing people in the right direction — away from POP3 and toward IMAP (or Exchange.)

Why POP3 is Bad

POP3 is just outdated. It comes from a time when everyone accessed their email in a desktop email program on a single computer. You probably had an email address through your Internet service provider and they provided a tiny amount of email storage no their server — perhaps 10MB or so. When you opened your email program, it would download all the new emails from your email provider and save them to your computer. It would then delete the emails from your online email account. This was necessary at the time — you only had a few megabytes for email storage on the server, and you needed to keep it empty or emails directed to your address would start “bouncing” back to the sender.

This made sense in the 90s — given the limitations of the technology — but it’s a big problem today. Here’s why:

You can only access your email on one device. After you download the email to that device, you can’t access it on other devices. In an age where you probably have at least smartphone as well as a computer, this is bad. POP3 relies on downloading all your emails. So, if you have new emails with large attachments, you have to sit there and wait while your program downloads all your emails to your computer. Your emails are stored on your computer, not the web server. This means that you have to worry about manually backing up your email program’s archive. If your hard drive dies, you’ll lose those emails!

Some services try to bypass this limitation by not actually deleting emails when you access them from POP3. Instead, these services just mark them as read so they won’t be downloaded again. This is a dirty hack and it has a big problem, too:

Your email actions won’t synchronize between your devices. For example, if your email client downloads an email and you haven’t read it yet, it may just be marked as read on the server. Or, it may never be marked as read on the server, even after you read it. When you change an email’s read status, star it, delete it, or organize it into folders, these actions will only be saved in the email program on your computer. They won’t be synchronized online to all your other devices.

Why IMAP is Better

IMAP is a more modern protocol. Where POP3 just downloads everything to your device and manages it locally, IMAP is more of a syncing protocol. IMAP synchronizes all changes to the server and treats your email server — not your local computer — as the primary place your email is stored.

For example, if you access an email account with 1000 unread emails with IMAP, you can access them instantly. They don’t actually download until you open them — of course, you can configure your IMAP client to automatically download a certain number of emails. Email attachments don’t download until you view them, unless you configure your email account otherwise. When you open an email, it’s instantly marked as read on your device, the IMAP server (for example, in the Gmail or Outlook.com web interface), and every other IMAP client you use. If you organize your emails into folders, your organization will be synced online. If you delete an email, it will be deleted everywhere — not just on your local device.

While POP3 downloads all your emails and leaves you to manage them on your local device, IMAP just provides a “window” to your email account. In a world where you have more than one device — or just want to leave your email online so you don’t have to worry about backing up and importing desktop email archives — IMAP is the best solution.

How to Use IMAP

IMAP is just an you choose when you set up your email account in a desktop, smartphone, or tablet email program. Older desktop email programs may be configured to use POP3 by default, but even the Mail app on iOS and the Email app on Android support POP3 email accounts.

Modern email programs should automatically default to using IMAP instead of POP3. Go into your email app and check to make sure it’s using  IMAP and not POP3 for your email account!

But My Email Program or Service Doesn’t Support IMAP!

If you’re using an email client that doesn’t support IMAP, it’s long past time to upgrade. Get a more modern email client today — on the desktop, Mozilla Thunderbird is a solid email client by the makers of Firefox, and Microsoft Outlook is very powerful option if you’re already paying for Microsoft Office.

If your email service doesn’t support IMAP and only supports POP3, it’s also a good idea to move on. For example, if you have an Internet service provider that still offers 10 MB of email storage you can only access over POP3, they probably haven’t upgraded their email service in 15 years. You should probably move along to a more modern service. Services like Gmail and Outlook.com can fetch email from your old account over POP3 so you can get it all in one place.

RELATED: How To Combine All Your Email Addresses into One Gmail Inbox

There’s really no good reason to use POP3 anymore when you can use IMAP. Yes, POP3 can ensure your emails are deleted from the email account and only stored on your local device, but that doesn’t help much — your emails are transmitted in plaintext anyway, so anyone monitoring Internet traffic can just archive copies of them. Email’s just fundamentally insecure that way, and POP3 certainly doesn’t make it more secure.

Image Credit: Digitpedia Com on Flickr (edited)