Post Office Protocol
Post Office Protocol (POP)
The Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. POP operates over TCP/IP connections, normally on port 110. POP version 3 (POP3) is the most recent version in common use and is defined in RFC 1939.
Operation
When an e-mail client connects to a mail server using POP, it typically downloads all the messages stored on the server for the particular user's e-mail address. Once downloaded, the messages are typically removed from the server, although many POP clients offer the option to leave copies on the server for a specified period of time.
Advantages
- POP is widely supported by most e-mail clients and servers.
- It allows users to access their emails even when they are not connected to the internet.
Disadvantages
- By default, POP3 downloads messages to the client device, which means if the device is lost or damaged, the messages may be lost unless they have been backed up.
- POP3 does not support server-side folders or organization of emails.
Alternatives
Alternative protocols for retrieving e-mails include Internet Message Access Protocol (IMAP), which allows users to view and manipulate messages without downloading them to their device.
