Network Protocols and Packet Switching: Question 10
Syllabus 14.1
A retired hobbyist checks his personal email using a single, old laptop that is permanently switched on at home, and he never needs to read his email from any other device. His mail provider gives him only a small amount of storage space on its server, so he wants every message downloaded fully onto his laptop and then removed from the server, to free up that limited space.
Which application-layer protocol is most suitable for retrieving his email in this way?
Show worked solution Hide worked solution
Worked solution
Why B is correct
The hobbyist only ever uses one device, never needs his mailbox to be kept synchronised across several devices, and specifically wants messages removed from the server once downloaded, to free up his limited storage space. POP3 (Post Office Protocol version 3) is designed exactly for this: it downloads each message fully onto the connecting device, and can then delete that message from the mail server, freeing up the server’s storage. This matches the hobbyist’s situation exactly, so B is correct.
Why the other options are wrong
- A (IMAP) is wrong: IMAP is designed to keep messages, and the mailbox’s folder structure, stored on the server and synchronised across every device that connects, which is the opposite of what the hobbyist wants. His messages would keep taking up his limited server storage indefinitely instead of being freed up.
- C (SMTP) is wrong: SMTP’s role is sending/relaying a newly composed outgoing message to its next mail server, not retrieving messages that are already stored and waiting on a server.
- D (FTP) is wrong: FTP is a general-purpose file transfer protocol, used to transfer files between a client and a server. It is a separate application-layer protocol from the email protocols and is not used to retrieve email.
Final answer
- B. POP3 downloads each message fully onto the hobbyist’s single laptop and can then remove it from the mail server, freeing up his limited server storage space.