POP3 (Post Office Protocol 3)

Post Office Protocol 3 (POP3) is an email retrieval protocol that downloads emails from a server to a user's device. POP3 is an older protocol that was designed for use on a single computer, and it has some limitations compared to more modern protocols:

One-way synchronization

POP3 only allows users to download emails from a server to a client, and not the other way around.

No previewing

POP3 doesn't allow users to preview, search, delete, or organize emails on the server.

No synchronization between devices

Users must manually create or set folders and settings on each device they use.

No real-time synchronization

POP3 lacks real-time synchronization between the email server and the client.

POP3 is configured to listen on port 110 for plain-text transmission, and port 995 for encrypted communication via SSL/TLS.

POP3 is losing popularity as people use multiple devices to access their email. Internet Message Access Protocol (IMAP) is a better option for users who access their email from multiple devices, as it stores emails on the mail server.