What port number is used by the Post Office Protocol version 3 (POP3) for retrieving email?

The Post Office Protocol version 3 (POP3) utilizes port number 110 for retrieving emails from a mail server. This standard network protocol allows a client to access and manage emails stored on a server. When a user configures their email client, it typically connects to the mail server over port 110 to download messages, which can then be read offline.

In contrast, the other port numbers mentioned serve different purposes. Port 25 is primarily used for sending emails via the Simple Mail Transfer Protocol (SMTP), port 80 is designated for Hypertext Transfer Protocol (HTTP) web traffic, and port 143 is associated with the Internet Message Access Protocol (IMAP), which is another method of retrieving emails but with different functionality compared to POP3.