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What is an IMAP and POP3 mail and how are they different

23 mayo, 2021

When you go to configure your email account in a third-party client, you will almost always see that it offers you the same two options: do it using IMAP or POP3. These are the two most popular email protocols out there, although the way they work and use your emails is quite different.

For this reason, it is usually important to know the differences to choose the one that best suits how you want to configure your account and that the emails that remain on the server are managed. And that is precisely what we are going to do, explain quickly and easily the differences between the two so that the choice is as simple as possible.

What are the IMAP and POP3 protocols

The IMAP (Internet Message Access Protocol) protocol has as its main characteristic that check emails directly on the server in the cloud of the company with which you have your account. This allows emails to be synchronized without problems if you use them from different devices or the web client of the service.

On the other hand, the main disadvantage of completely delegating to a server in the cloud is that in principle you need to connect to the Internet every time you want to check your mail, and that you have to review your account to avoid reaching the server space limit. Fortunately, as of today these problems are already solved by some mail applications that allow you to download the emails and check the free space you have left on the servers.

Regarding the POP3 protocol (Post Office Protocol 3), it connects to the server where the emails are hosted and download them all to the device in which you have configured the account, allowing you to read them offline. When you download the emails they are deleted from the server, although there are also clients that eliminate this setback allowing you to keep them.

Therefore, we have an apparently more advanced and optimal IMAP protocol to be used from various devices, something important in an age of smartphones coexisting with computers. On the other hand, POP3 may seem a bit more rudimentary, but it can offer some advantages to certain types of user.

Advantages and disadvantages of IMAP and POP3




  • Emails stay on the server
  • All emails can be accessed from any device
  • The directories that you create in your mail program will also be created on the server, and will always be accessible.
  • Two-way communication between mail server and client, changes made from one device are seen on the others
  • It is always possible to retrieve emails
  • Faster by downloading messages just by clicking on them
  • It is not necessary to have a lot of storage on the mail server
  • More privacy
  • You can always read emails offline
  • Some clients prevent emails from being deleted from the server


  • You have to watch the server space limits.
  • It may not work well offline in some mail client
  • The directories and tags that you create in your email program will remain configured only in that application, and not at the server level.
  • Danger of losing emails.
  • In the case of not deleting the emails on the server, when reading an email on one computer they will continue to be unread on the others
  • Doesn’t work well from two devices at the same time

As you can see from the table, currently the IMAP protocol is the one that offers the greatest advantages. It is recommended if you are going to use the same email account from several devices, since it applies all the changes on the server, and any folder or label that you create will be synchronized on the rest of the devices.

The great advantage of the POP3 protocol is that it is designed to work offline, but nowadays Most third-party clients allow IMAP emails to be downloaded locally. Therefore, apparently it only has the advantage of the little space necessary, something that can be attractive if we use a service with limited memory beyond Gmail or Outlook.

Every time you connect with your client through POP3, it reads all the emails that you have hosted on the server and downloads them, which makes run somewhat slower. Also, emails are usually deleted when they are downloaded, so it can be quite chaotic to use it on two different devices.

And even if your client allows you not to delete messages from the server, what you do locally will not be synchronized online, so you will not appreciate the changes when you connect from another device. Come on, just the opposite of what happens with the IMAP protocol.

Despite these disadvantages, POP3 can still be a good option for those who want to maximize their privacy. Therefore, if you do not want your emails to be stored and always synchronized on the servers of a third company, you may be interested in resorting to this protocol.

But for everything else, in most cases the most comfortable thing will always be to resort to the IMAP protocol, especially when you are using an account that you want to access from several devices at the same time.

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