What is POP in email?

Email is one of the most ubiquitous forms of communication in the modern world. Most people have at least one email account that they use for personal or work purposes. Email allows us to send messages, attachments, photos, and more to anyone else with an email address. There are different protocols that enable access to our email on different devices – POP and IMAP being two of the most common.

So what exactly is POP or “Post Office Protocol”?

What is POP in email?

How POP email works

POP or Post Office Protocol is an email retrieval protocol that allows you to download email messages from your email server onto a local device or computer app. Here’s a quick rundown of how POP works:

  • Emails are stored on a mail server provided by your email service until they are retrieved
  • Email clients like Outlook or the Mail app on your phone use POP to connect to the mail server
  • Once connected, the email client can download message content from the server onto your device
  • Messages are normally downloaded and removed from the server after being retrieved
  • Any changes made to downloaded messages are only saved in the local copy on your device

The key difference between POP and IMAP is that POP is designed for downloading messages, while IMAP keeps everything synchronized across devices.

Some key benefits of POP include:

  • Simple to set up – Just need the server details and login credentials
  • Good for local storage – Downloads emails from the server onto your device
  • Lower server space requirements – Messages are removed from server after download

And some potential downsides:

  • No synchronization – Changes on local devices aren’t updated back to the server
  • Only one client can access messages – Other devices won’t see emails downloaded to your main device

How POP differs from IMAP

IMAP or Internet Message Access Protocol is the other most common email retrieval protocol along with POP. The main differences include:

Emails are downloaded and removed from server Emails are synchronized across multiple devices
Access email from one application at a time Simultaneous access from multiple email clients
New messages not visible across devices Changes reflected across connected devices
Good for storage on local computer Requires more server storage space

As you can see, POP is good for downloading emails to one local computer or device while IMAP keeps everything in sync across multiple applications.

Many email providers now allow you to use either protocol. Choosing between POP vs IMAP depends on your usage patterns and whether you need access to the same email across multiple devices and locations.

POP email server settings

To access your email via POP, you will need to configure the POP settings in your email client with the details provided by your email provider.

Here are the typical settings required:

  • POP server – Server address for incoming mail
  • Security type – Unencrypted or SSL/TLS encryption
  • Incoming port – Usually 110 for unencrypted, 995 for SSL
  • Outgoing port – Usually 25, 465 or 587
  • Account username & password

You can get the right settings for your email account from your email provider or domain administrator. As the ports may vary across providers, it’s always best to look up the recommended configurations.

Accessing email from multiple clients

A limitation of using POP is that generally only one email client can access the inbox at any time. Once messages are downloaded via one client, other mail apps won’t have access unless they also use POP to retrieve mail from the server.

To allow simultaneous access from multiple devices and locations, IMAP would be the preferred protocol. As the same messages are synced across different applications in IMAP, you can access the same inbox from your phone, laptop, PC and other devices seamlessly.

Pros and cons of POP vs IMAP

Pros – Easy to set up <br> – Downloads messages for offline access <br> – Frees up space on mail server – Access same inbox from multiple clients <br> – Changes synced across devices <br> – No need to download all messages for offline access
Cons – Mail only available on one device at a time <br> – Changes not synchronized <br> – Can’t access email without connectivity <br> – Have to upload sent mail – More complex to configure <br> – Uses more server storage space <br> – Fetching messages can be slower

When to use POP vs IMAP

Here are some guidelines on when POP or IMAP might be preferable:

POP is best for:

  • Checking emails mainly from one computer
  • Saving messages to your local machine
  • Freeing space in your webmail account
  • Simple email access from one location

IMAP works better if:

  • You need access your inbox from multiple devices
  • You send and receive lots of emails frequently
  • You want sent/received emails to be synced
  • You connect from multiple locations

If you need flexibility, most modern email services let you use either protocol and switch between the two. Just be aware of the synchronization and accessibility limitations when deciding on POP vs IMAP.

Email client compatibility

Most popular email clients and providers support both POP and IMAP configurations nowadays.

Here are some of the common email providers and applications compatible with POP and IMAP:

  • Webmail services – Gmail, Outlook.com, Yahoo Mail, GMX, Zoho Mail
  • Email applications – Microsoft Outlook, Apple Mail, Mozilla Thunderbird
  • Mobile apps – Default mail apps on iOS and Android devices
  • Email forwarding services – Forwards received messages to another account

So you should be able to use POP capabilities with the most common email platforms and devices. Just ensure you have the appropriate settings configured.

Securing POP email access

As your email messages will be downloaded from the mail server onto your local computer when using POP, it’s vital to use proper security measures.

Here are some ways to keep your POP email access safe:

  • Always use SSL/TLS encryption for transmission of usernames, passwords and downloading messages. Avoid unencrypted POP.
  • Strong passwords that would be difficult for anyone else to guess. Enable two-factor authentication if available.
  • Local encryption – Encrypt local storage of messages if your device is ever lost or stolen.
  • Avoid accessing POP emails on shared or public devices and networks.
  • Antivirus software to protect against malware trying to access downloaded emails or passwords.
  • Email client lock – Password protect your mail application.
  • Secure account recovery options in case your credentials are ever compromised.

As long as you follow general email security best practices, accessing your messages via POP should not present any significant risks beyond the usual webmail scenarios.

POP in email – Key Takeaways

  • POP or Post Office Protocol allows you to download emails from a server onto a local device via an email client.
  • Key POP capabilities are downloading messages for storage and removing them from the server.
  • Unlike IMAP, changes to downloaded messages are not synchronized back to the server in POP.
  • Only one email client can access the inbox at a time with POP, while IMAP allows simultaneous multi-device access.
  • POP is good for offline email access from one main computer. IMAP works better if you will be accessing mail frequently from multiple locations and devices.
  • Most common email providers and applications support POP capabilities and related settings.
  • It’s important use encryption and general email security best practices when using POP.


POP or Post Office Protocol facilitates efficient downloading of email messages from a mail server onto a local computer or device. While simple to configure, it does have limitations like one client accessibility and lack of synchronization. For most users, the choice between POP vs IMAP will depend on whether you primarily use email from a single location or need access from multiple devices and places. Both protocols help enable offline access and storage with good security measures. Understanding the core differences allows you to pick the right email retrieval method based on your specific access patterns.

Frequently Asked Questions

  1. What is POP3 email?
    POP3 stands for Post Office Protocol version 3, which is the most common POP standard used for retrieving emails from remote servers. The current version is POP3, which added additional security features like Transport Layer Security (TLS).
  1. How does POP3 work?
    The POP3 protocol allows an email client to connect to a mail server, authenticate via username and password, then download messages into local storage. Once the emails have been downloaded, the mail server deletes the stored emails to free up space.
  1. What is the difference between POP, IMAP and SMTP?
    POP and IMAP handle retrieving emails from a mail server. SMTP deals with sending emails. POP downloads messages then deletes them from the server, IMAP synchronizes messages across multiple devices and leaves them on the server.
  1. What is the POP3 port and connection?
    The default POP3 port is 110 for unencrypted connections. For SSL/TLS encrypted connections, POP3 uses port 995. Authentication is required using your email login credentials to download messages via the POP3 protocol.
  1. Is Gmail POP or IMAP?
    Gmail supports both POP and IMAP to view and synchronize your Gmail emails on email clients and apps. You can enable either protocol in your Gmail Settings.
  1. Can I use both POP and IMAP at the same time?
    Most modern email providers and servers allow you to use both POP and IMAP at the same time. However, it is generally recommended to choose one primary protocol to avoid conflicts between POP downloading messages and IMAP trying to synchronize messages.
  1. Is POP3 secure?
    Unencrypted POP3 connections are not secure and transmit usernames, passwords and entire messages without encryption. Using SSL/TLS encryption via POP3S (default port 995) encrypts the POP3 session and prevents unauthorized access.
  1. Why am I not receiving emails in my POP3 account?
    Some troubleshooting tips if you stop receiving new POP3 emails: Check your network connection is up, verify if the mail server is working, double check your encryption settings match the server, test with telnet if the POP3 port is accessible, try reauthorizing the account.
  1. How do I back up my POP3 emails?
    As the POP protocol downloads messages into a local email client for storage, you simply need to back up your email application’s data file or local folders containing the message cache. This can be done manually or via your normal computer backup procedures.
  1. Can I access POP3 email on my phone?
    Yes, most mobile devices and their default mail apps support POP3 capabilities. Add a POP3 account in your phone’s Settings or Mail app, entering details like the mail server address, username, password, encryption method etc. to access POP3 workplace or email provider accounts on-the-go.
  1. Is POP3 still used today?
    While IMAP is growing in popularity, many email providers and users still utilize POP due to its simplicity and offline access capabilities. As one of the earliest and most widely supported email protocols, POP3 remains relevant even as newer standards emerge.
  1. What are the advantages of POP3?
    POP3’s main advantages are: very easy to set up, requires less storage space on mail servers, allows offline access to emails once downloaded, provides stable and reliable performance. These benefits make it a time-tested, useful protocol.
  1. What are the disadvantages of POP3?
    Some disadvantages of POP3 include only being able to access emails from one device/client at a time compared to IMAP synchronization, lack of backup access to messages deleted on the mail server, no cloud-based features, and less secure than modern alternatives.
  1. When should I use POP3 instead of IMAP?
    In general, POP3 makes more sense for individual email users who want to download emails to a single main computer for storage. People who need access to the same inbox across multiple devices are better served by IMAP synchronization.
  1. Can POP3 and IMAP emails be combined in one folder?
    Yes, most modern email clients support accessing both IMAP and POP3 mailboxes, with the option to either keep them separate or merge them into combined folders within the email application if desired.
  1. Is Yahoo Mail POP or IMAP?
    Yahoo Mail supports both POP and IMAP protocols to sync your Yahoo email with other email clients. You can find options to enable both POP and IMAP under Settings > Accounts in the webmail interface.
  1. Can you set Gmail to always use POP3?
    Yes, in your Gmail account settings, you can configure your account to always download messages using POP3 instead of accessing them directly from the Gmail web interface. This will force Gmail to follow POP3 behavior across all email clients.
  1. What is better for Gmail POP or IMAP?
    For most Gmail users, IMAP is recommended for easy access across multiple devices and platforms. However, POP3 can be useful for those who want to primarily download messages directly to their main computer without taking up storage space in Gmail.
  1. Where do my messages go after downloading POP3 email?
    By default, most email clients will store downloaded POP3 messages in a local storage folder or database. The location varies across different applications but is usually easy to access to view messages offline.
  1. Can I restore POP3 emails after downloading?
    Unfortunately, no. A downside of POP3 is after the messages are downloaded via POP and deleted from the server, the mail server no longer has access to those emails to restore. Only the local copies are retained, so backups are important.

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