Question

Which of the following Application layer protocols is used to support electronic mail?
1. SMTP
2. IP
3. TCP
4. UDP

Answer 1

Correct Answer - Option 1 : SMTP

SMTP

• Simple Mail Transfer Protocol (SMTP) is the standard protocol for sending emails across the Internet. Therefore, SMTP transfers messages from the sender’s mail servers to the recipient’s mail server.

TCP:

TCP is the transfer layer protocol. Electronic mail function is supported by the transfer layer protocol TCP. TCP is a connection-oriented and reliable transport protocol. Therefore, SMTP transfer messages from the sender’s mail servers to the recipient’s mail servers using TCP

UDP:

• UDP is an unreliable connectionless-transport layer Protocol used for its simplicity and efficiency in applications where error can be provided by the application layer
• UDP provided process-to-process communication