What Is POP3 (Post Office Protocol 3)?

POP3 is an abbreviation for Post Office Protocol 3, and it is the third version of a widespread method of receiving email. 

An email protocol is the programmed system of defined rules that govern the exchange of emails between servers and email clients. The reason that your emails arrive with consistency is because of your email protocol. 

Should you use POP3, or is one of the other protocols (SMTP or IMAP) better for your needs? The best way to make the decision is to find out more about each of your options.

How Does POP3 Work?

A well-known analogy for POP3 is to think of your email like physical mail, and think of your email server as a post office. POP3 is the mail clerk. 

When you go to the post office to pick up your mail, it’s right there, waiting for you. The post office clerk has saved it for you. POP3 is the clerk, holding your email until you’re ready to pick it up. 

However, the post office doesn’t make any copies of your mail. Once you pick it up, the post office and the clerk no longer have access to it. 

In the previous version of POP3, when an individual downloaded their email from the server into their email program, there were no more copies of the email on the server; POP automatically deleted them. 

That is still the default setting for POP3 accounts. However, you can configure many POP3 programs to temporarily save emails on the server. A general recommendation is to leave them on the server for 14 days before they are deleted. 

POP3 makes it easy for anyone to check their email from any computer in the world, provided they have configured their email program properly to work with the protocol.

Mail Server Functionality

POP3 has become increasingly sophisticated so that some administrators can configure the protocol to “store” email on the server for a certain period of time. This allows an individual to download their email as many times as they wished within that given time frame. 

However, this method is not practical for the vast majority of email recipients, and POP3’s default configuration deletes all of the emails from the server, either immediately or within a couple of days. 

While mail servers can use alternate protocol retrieval programs, such as IMAP, POP3 is extremely common among most mail servers because of its simplicity and high rate of success. Although the newer version of POP offers more “features,” at its basic level, POP3 is preferred because it does the job with a minimum of errors.

For most users, if you’ve decided to check your email from multiple devices, any message that was previously downloaded will not be available on the new device. 

Working With Email Applications

Because POP3 is a basic method of storing and retrieving email, it can work with virtually any email program, as long as the email program is configured to host the protocol. Many popular email programs, including Eudora and Microsoft Outlook, are automatically designed to work with POP3. 

Each POP3 mail server has a different address, which is usually provided to an individual by their web hosting company. This address must be entered into the email program in order for the program to connect effectively with the protocol. 

Generally, most email applications use the 110 port to connect to POP3. Individuals who are configuring their email program to receive POP3 email will also need to input their username and password in order to successfully receive email.

Advantages and Disadvantages of POP3

There are two main advantages of using POP3.

1. Access some of your email without an internet connection

You can read any of your already-downloaded emails on your device without needing to connect to the internet. This is great news for people who need to work or access their email history, regardless of where they are or how reliable their internet connection may be. 

After all, they’re already downloaded to your device. You don’t need to access the server to view those emails because they’ve already been deleted from the server anyway.

Of course, you will still need to connect to the internet to access any new and unread emails.

2. You will need far less server space

As emails are automatically deleted from the server, your server space never gets cluttered or overwhelmed by a huge backlog of email data. Even though it may be inconvenient at times to store all of your emails on your device, you do get the benefit of a reduced need for server space. 

Drawbacks of POP3

Unfortunately, POP3 does come with some disadvantages, including:

• Lack of back-up. If the device storing your email breaks down, you won’t be able to retrieve any emails. 
• No instant push notifications as emails arrive. Instead, you’ll need to set up your email system to check the server periodically for any new messages.
• Emails can’t be marked as “read” on multiple devices. Any time you use a different device to access the server, all of the emails will be marked as unread. 
• No automatic organization into folders. You’ll have to filter all of your incoming emails into folders manually, which can be pretty time consuming. 
• You can only send messages from one device. 

What About IMAP?

Internet Messaging Access Protocol (IMAP) is the main alternative to POP3. 

In an IMAP system, the server stores your emails, even after delivery. Your email doesn’t get downloaded or stored on your device, and you can only access your sent, received, and new messages when you are online. 

The only significant drawback to IMAP is that you need to be online in order to access your email. 

Benefits include: 

• Faster access to your email (no waiting for slow downloads)
• Less data usage on your smartphone
• Sent emails are accessible from anywhere
• Use as many devices as you want and have the exact same email experience on all of them

If you know that you are going to be offline for a period of time, you can configure IMAP to temporarily store your emails on your device for offline access.

The Final Word on POP3

POP was one of the most important early developments in email technologies. 

Many people still use POP3 to this day, and many email servers can be configured to work as POP3 or IMAP systems, depending on the user’s specific needs. 

POP3 is losing some popularity over time, especially as people’s email habits change. Most people today use multiple devices to access their email, including smartphones, tablets, laptops, and desktops. IMAP’s functionality is better for these users. 

Still, POP3 is not some kind of dinosaur! It is still very useful and consistent, and many email users will continue to use it in the years to come. 

Related Articles

• What is a mail server?
• What is SMTP?
• What is IMAP?
• Email basics