The correct answer is option 1. POP stands for Post Office Protocol. It provides a standard mechanism for retrieving emails from a remote server for a mail recipient. In simple terms, a user who wants to receive emails but does not have a permanent connection to the internet uses a POP client to pull emails from the POP server.Hence the correct answer is POP server.Additional InformationSMTP stands for Simple Mail Transfer Protocol, and SMTP server is an application used by mail servers to send, receive, and/or relay outgoing mail between email senders and receivers.Database servers are networked computers on a network dedicated to database storage and data retrieval from the database. The database server is a key component in a client/server computing environment. It holds the database management system (DBMS) and the databases.