three protocols used in mail service server-client model and describe their use.

The three protocols used in mail service server-client model are SMTP (Simple Mail Transfer Protocol), POP3 (Post Office Protocol version 3), and IMAP (Internet Message Access Protocol).

SMTP is used for sending messages from a client to a server or between servers. It is responsible for the actual transmission of the email message.

POP3 is used for retrieving email messages from a server to a client. It allows users to download messages from the server to their local device and manage them locally.

IMAP is similar to POP3, but it allows users to manage their email remotely. This means that messages are stored on the server and users can manage them from any device.

Overall, SMTP, POP3, and IMAP are used together to provide a complete email service that allows users to send, receive, and manage their messages from different devices and locations.