POST OFFICE PROTOCOL (POP)

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 **** Post Office Protocol ****
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Post Office Protocol (POP) is a simple protocol used for opening the remote email boxes. This protocol is defined in RFC 1225.
Post Office Protocol version 3 (POP3) provides mechanisms for storing message sent to each user and received by SMTP in a receptacle called a mailbox. A POP3 server stores message for each user until the user connects to download and read them using a POP3 client such as Microsoft Outlook 98, Microsoft Outlook Express, or Microsoft Mail and News.

To retrive a message from a POP3 server, a POP3 client establishes a Transmission Control Protocol (TCP) session using TCP port 110, identifies itself to the server, and then issues a series of POP3 commands::


(a) stat: Asks the server for the number of messages waiting to be retrieved.

(b) list: Determines the size of each message to be retrived .

(c) retr: Retrieves individual message.

(d) Quit: Ends the POP3 session.

Note :; After a POP3 client reads a message in its mailbox on a POP3 server, the Message is deleted. Primarily because of this, POP3 is being supplanted by Internet Mail Access Protocol version 4 (IMAP4), which offers better support for mobile users. POP3 is supported by Microsoft Exchange Server.

See Also ::
1.SMTP
2.FTP
3.NFS
4.SNMP
5.Types of Computer Attacks