POP3, Post Office Protocol: What is it, what is it for and how is it different from IMAP?

Email is one of the most important tools for communication between people and companies around the world. It came to replace the traditional communication by letters through postmen used in almost all countries. Thus offering a greater speed of delivery and security.

In order for these mail servers to function properly and at high speed, they need to be within certain standards, which allows the system to be secure and transparent.

It is also important to mention that the emails have protocol tools, which are responsible for ensuring the sending and receipt of each of the messages. Currently there are three fundamental protocols: IMAP, POP and SMTP. With this in mind, here we will teach you a little more about the POP3 protocol.

What is the POP3 “post office protocol” and what is it used for in a network?

This protocol used in computing known as Post Office Protocol is used to obtain the messages that are sent by email and stored in a remote server, which is known as POP.

POP has different versions, where both POP1 and POP2 versions have become old due to the appearance of the new POP3 version. It has been designed mainly to help its users with the use of the server, especially when they have a slow connection.

This is how users can download their email so that they can later check it even on those occasions when they do not have an Internet connection. In addition, the Post Office Protocol, has been designed to receive email and not to send them or at least not always.

In other words, the main function of this is that a client connects and gets all the messages it has in the mail, there downloads them to the computer and then removes them from the server and disconnects. This way you can check them without being connected.

What are the main characteristics of the POP protocol and how does it work?

When we refer to POP3, we are referring to the latest version of the POP protocol, which started in the early 1980s, when two previous versions, POP1 and POP2, were released, which have become obsolete over time. In addition, this POP protocol is currently the most used in email servers, being used by Windows Mail, Gmail, Outlook, among others.

It is also frequently used by applications and services that are in charge of collecting messages in the email server, working simultaneously with SMTP, another mail protocol.

With this in mind, here we show you its main features:

  • It gives you the ability to leave messages on the server.
  • It has three versions since its release, where currently only works POP3 being this the most recently launched.
  • It gives your users the possibility to download the emails to their computers to read them without having an internet connection, or when the connection is very slow.
  • Every time the user connects to the server the e-mail messages are sent from the server to the local computer.
  • Once the messages have been received, the connection with the server can be interrupted or closed, this will not affect the reading of the messages.

Versions of the POP How many are there and what are their characteristics?

This electronic mail protocol began to work in 1980, since then it has managed to have a total of three versions, where its first two have already become obsolete following new advances in technology. Thus, in 1984 the first version of this protocol was officially known and it would only last for one year.

Thus, in 1985 the second version called POP2 was released and assigned port 109 as the default. This version would also last a short time in the market, so for 1988, the last version called POP3 was released, and which is still active today.

This is the one that will allow you to download all your emails to your computer and thus be able to read them without the need to stay connected to the computer or have an Internet connection. This is a very important feature for most users who have a slow Internet connection.

How to set up POP3 on the main email services?

In case you want to configure POP3 in your email to start enjoying its benefits, especially to be able to use it without having an Internet connection, then here we will explain how you can make this configuration in the main email services. To do this, follow each of these methods that we will show you below:

Google Gmail

In the case of Gmail, you can only set up your account with POP and not IMAP, which means you can download each of your messages, but they don’t sync with the server. Also, you can only download the messages you have in your inbox; messages in other folders can’t be downloaded.

It is also important to clarify that those emails you download to your PC will be deleted from the server by default. Therefore, the best thing to do in this case is to check the box to leave a copy on the server.

With this in mind, here’s how to set up POP3 in Google Gmail:

  • Log in to Gmail and sign in with your login information.
  • Once you have logged into your inbox, click on the wheel icon at the top right of your screen.
  • In the options that have been displayed, select “Configuration”.
  • Here you click on “Account and Import” located in the top menu.
  • Then select the option “Add an email account”.
  • Next, enter the email address you’d like to add to Gmail.
  • Once added, click “Next”.
  • Please note that some of the accounts are linked to Gmailfy, which is not available for accounts hosted with One.com. Therefore, the next step is to confirm that you want to import with POP.
  • Here we select the section “Import mail from my other account” and select “Next”.
  • Once this has been done, the data from the POP3 server must be entered. It is recommended to use this configuration for incoming mail:
    • Username: Your email address.
    • Password: The same as the email.
    • POP:one.com server
    • Port: 995
  • Check the box “Leave a copy on the server” and “Use SSL”.
  • Next, select “Add Account” to continue.

Once this is done, the protocol to the Gmail account will be configured, so you can start enjoying its services and benefits.

Microsoft Outlook/Hotmail

In case you have an Outlook account and want to add it to another mail program that uses POP then you need to know this data. Note that by default, access to POP is disabled, so it must be activated for use.

  • POP server name: Office365.com
  • POP port: 995
  • POP encryption method: TLS

Knowing this data we can enable POP in the Outlook account. Therefore, to be able to configure and have access to the protocol it is necessary to enable access to it.

To do so, follow these steps:

  • Go to the “Settings” of your Outlook account.
  • There you select the option to view all your Outlook settings.
  • Then select the “Synchronize your email” section.
  • Now in the POP option, check the box “Yes” under “Allow devices and applications to use POP”.
  • Finally click on “Save”.


If you are a Yahoo! user and have a free account you can also start using the POP3 service, taking into account that this was only available to paid users. This will help you get improvements in the service, especially because it will allow you to receive the emails directly in your PC and check it no matter if you have an Internet connection.

The data you need to set up POP is as follows:

  • Incoming mail server POP3:mail.yahoo.com
  • Port of entry: 995
  • Outgoing mail server: mail.yahoo.com
  • SSL/TLS output port: 465, 587, 25
  • Requires an email and password authentication
  • The email address will be the same as your yahoo!
  • The password will be the same as the one used to log in to your Yahoo! account.

With all this data in mind, you can start activating POP3 in your Yahoo! account,

To do so, follow the steps we will show you below:

  • Login to your Yahoo! account and in the upper right hand corner of your screen select the “Options” tab.
  • There you will see several options where you select “Mailing Options”.
  • In the new window that appears, select the section “POP3 Access and Forwarding”.
  • Then check the option “Web access and POP3”.
  • Finally select “Save”.

When you have done all this, you will be ready to start downloading your emails directly to your computer.

POP3 or IMAP Which is better and how is each different?

POP2 and IMAP are standard Internet protocols used for emails and allow your program to access users’ email accounts on your web space.

In the case of IMAP, it works directly on the mail server, therefore, in order to consult the emails you have to connect to the server that will show you the content stored there. At the time of sharing a message is usually stored on the server being accessible from any other device where you enter the account.

One of the advantages of this protocol is that the mail is accessible from any device as long as it has Internet, also work directly with the server and the emails have a kind of security because they are not lost or deleted from the server being stored there.

While in the case of POP3, it connects to the server and downloads all messages to the computer. However, the messages are automatically deleted from the server, which means that there is no backup, and they are stored only on the local device.

But the current managers offer an option that will allow you to save a kind of copy of the emails that are downloaded from the server. In addition, it allows you to keep a history of local mail without the need for a network connection. By deleting the downloaded messages, the server always has available storage space.

POP3 or SMTP protocol What are the differences between the two and which is better?

Each time an email is sent and received, the action of two protocols is required, where one must be a message transfer agent, while the other must be a message access agent. In this case the transfer agent is in charge of transferring the data from the PC to the server, and the access agent’s job is to extract the data from the server’s mailbox and transfer it to the recipient’s computer.

In this case the transfer agent is SMTP, and the access agent POP3, and also acts as an IMAP access agent. Therefore, one of the main differences between these two is that SMTP is a transfer agent while POP3 is an access agent used to receive messages.

We can also say that in the case of SMTP it is a simple mail transfer protocol, where it helps to transfer the information from the sender’s computer to the mailbox present on the receiver’s server. In the case of POP3, it is an email office protocol version 3, and its purpose is to retrieve and organize the mailboxes in the receiver’s server to the receiver’s computer. Its main function is to receive the messages and download them to the computer.

This post is also available in: Português (Portuguese (Brazil))

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