Internet Business Tutorial 10

by Robert H. Fraass on Friday, March 11, 2005
SMTP/POP3/IMAP-Simple Mail Transfer Protocol/Post Office Protocol 3/Internet Message Access Protocol
Just like TCP and IP work together to govern communications over the Internet, Simple Mail Transfer Protocol (STMP) and Post Office Protocol 3 (POP3) set the rules for the transfer of electronic mail (e-mail).
SMTP is the protocol used to transfer e-mail messages from server to server. For example, when you send an e-mail message to someone at a different company, the message first goes to your company's server and then to the server of the other company. SMTP governs this server-to-server transfer.
POP3 is the protocol an e-mail client needs to receive this same e-mail message from the server. The e-mail client uses POP3 to communicate with the server and obtain the message.
The POP3 standard is being replaced with the Internet Message Access Protocol (IMAP), which has improved functionality over POP3, including manipulating messages stored on a server-such as viewing a message heading and its sender-without actually downloading them by opening the messages. This feature, for example, is found in the Microsoft Outlook e-mail client