Which of the following protocols allows an e-mail client to access e-mails that are stored on a
remote mail server?
A.
PPPoE
B.
ICMP
C.
IMAP
D.
SMTP
Explanation:
IMAP stands for Internet Message Access Protocol. This protocol helps to retrieve e-mail messages
stored on a shared e-mail server. Through
this protocol, a user can use a client e-mail program/Mail User Agent (MUA) for downloading an email from the shared server. A user can also
use this protocol to edit or delete an e-mail from the shared e-mail server. An example of the IMAP
protocol is the POP3 protocol that is quite
simple and used for retrieving e-mails from a mail server.
Answer D is incorrect. Simple Mail Transfer Protocol (SMTP) is a protocol for sending e-mail
messages between servers. E-mailing
systems use this protocol to send mails over the Internet. SMTP works on the application layer of the
TCP/IP or OSI reference model. The
SMTP client typically initiates a Transmission Control Protocol (TCP) connection to the SMTP server
on the well-known port designated for
SMTP, port number 25. However, e-mail clients require POP or IMAP to retrieve mails from e-mail
servers.Answer A is incorrect. Point to Point Protocol over Ethernet (PPPoE) is a specification for
establishing PPP connections through Ethernet
network adapters. It connects users on an Ethernet to the Internet through a common broadband
medium, such as a single DSL line or cable
modem. PPPoE is described in RFC 2516.
Answer B is incorrect. Internet Control Message Protocol (ICMP) is a maintenance protocol and is
normally considered part of the IP
layer. ICMP messages are encapsulated within IP datagrams, so that they can be routed throughout
an internetwork.