11th September 2008 9:13 PM
POP3 (Post Office Protocol) is the most common protocol used to retrieve e-mail from a mail server.
Most e-mail applications (sometimes called an e-mail client) use the POP protocol, although some can use the newer IMAP (Internet Message Access Protocol).
The newest version, POP3, can be used with or without SMTP (an email sending protocol, stands for Simple Mail Transfer Protocol). The first version, called POP2, became a standard in the 1980s and required SMTP to send messages