====== POP3 (Post Office Protocol Version 3) ======

**POP3 (Post Office Protocol version 3)** is a protocol used to **download email from a mail server**.

Unlike IMAP, POP3 is designed primarily for a single device.

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===== How POP3 Works =====

A typical POP3 session:

  * Connect to the mail server.
  * Download new messages.
  * Optionally delete them from the server.
  * Disconnect.

<code>
Mail Server
      │
      ▼
Computer
      │
Messages Downloaded
</code>

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===== Common POP3 Ports =====

^ Port ^ Purpose ^
| 110 | POP3 with STARTTLS |
| 995 | POP3 over SSL/TLS (recommended) |

Port **995** is recommended.

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===== Advantages of POP3 =====

  * Simple protocol
  * Works well with one device
  * Allows offline reading
  * Reduces server storage usage

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===== Disadvantages of POP3 =====

  * Poor synchronization
  * Messages may disappear from the server
  * Folders are usually stored locally
  * Not ideal for multiple devices

-----

===== Keep a Copy on the Server =====

Many email clients offer:

<code>
Leave messages on server
</code>

When enabled:

  * Messages remain on the server.
  * Other devices can still access them.

-----

===== POP3 vs IMAP =====

^ POP3 ^ IMAP ^
| Downloads mail | Synchronizes mail |
| Usually one device | Multiple devices |
| Local storage | Server storage |
| Limited synchronization | Full synchronization |

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===== POP3 Security =====

Modern POP3 connections should use TLS.

Recommended configuration:

<code>
Port 995
SSL/TLS Enabled
</code>

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===== POP3 and Telenegar =====

The **Telenegar Mail Check** service can verify:

  * POP3 connectivity
  * POP3 TLS support
  * Certificate validity

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===== Common Misconceptions =====

  * **POP3 always deletes messages from the server.**
    * False. Most email clients allow you to keep a copy on the server.

  * **POP3 is obsolete.**
    * False. It is still used, although IMAP is preferred for most users.

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===== When Should You Use POP3? =====

POP3 is suitable when:

  * You use only one computer.
  * You want local copies of all messages.
  * Server storage is limited.

IMAP is usually the better choice when accessing email from multiple devices.

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===== Related Topics =====

  * [[email:imap|IMAP]]
  * [[email:smtp|SMTP]]
  * [[tools:mailcheck|Mail Check]]

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{{tag>email pop3 mail tls}}