This is an explanation post in response to Anil Kumar's question - a simple protocol used for fetching email from a mail box is. The question offers four possible option:
- POP 2
- POP 3
SMTP (Simple Mail Transfer Protocol)
The SMTP protocol is used by the Mail Transfer Agent (MTA) to deliver your eMail to the recipient's mail server. The SMTP protocol can only be used to send emails, not to receive them.
IMAP (Internet Message Access Protocol)
IMAP Is a standard protocol for accessing e-mail from your local server. IMAP is a client/server protocol in which e-mail is received and held for you by your Internet server. As this requires only a small data transfer this works well even over a slow connection such as a modem. Only if you request to read a specific email message will it be downloaded from the server. You can also create and manipulate folders or mailboxes on the server, delete messages etc.
Because SMTP is used to send emails (not to receive) and IMAP is for both sending and receiving purposes, these two options are not the correct answers. Now, we'll look into POP2 and POP3:
POP-2, often referred to as POP2 is a discontinued programming language developed around 1970 by Robin Popplestone and Rod Burstall at the University of Edinburgh from the earlier language POP-1 which was developed by Robin Popplestone in 1968, originally named COWSEL.
POP (Post Office Protocol 3)
The POP3 protocol provides a simple, standardized way for users to access mailboxes and download messages to their computers.
When using the POP protocol all your eMail messages will be downloaded from the mail server to your local computer. You can choose to leave copies of your eMails on the server as well. The advantage is that once your messages are downloaded you can cut the internet connection and read your eMail at your leisure without incuring further communication costs. On the other hand you might have transferred a lot of message (including spam or viruses) in which you are not at all interested at this point.
Thus, looking at the options provided, POP3 is the correct answer.