UNIT-V
1. What is the function of SMTP?
The TCP/IP protocol supports electronic mail on the Internet is called Simple Mail Transfer (SMTP). It is a system for sending messages to other computer users based
on e-mail addresses. SMTP provides mail exchange between users on the same or different computers.
2. What is the difference between a user agent (UA) and a mail transfer agent (MTA)?
The UA prepares the message, creates the envelope, and puts the message in the envelope. The MTA transfers the mail across the Internet.
3. How does MIME enhance SMTP?
MIME is a supplementary protocol that allows non-ASCII data to be sent through SMTP. MIME transforms non-ASCII data at the sender site to NVT ASCII data and deliverers it to the client SMTP to be sent through the Internet. The server SMTP at the receiving side receives the NVT ASCII data and delivers it to MIME to be transformed back to the original data.
4. Why is an application such as POP needed for electronic messaging?
Workstations interact with the SMTP host, which receives the mail on behalf of every host in the organization, to retrieve messages by using a client-server protocol such as Post Office Protocol, version 3(POP3). Although POP3 is used to download messages from the server, the SMTP client still needed on the desktop to forward messages from the workstation user to its SMTP mail server.
