How does Internet Message Access (IMAP) differ from POP3 in handling emails?

The choice indicating that IMAP retains emails on the server until manually deleted is correct because IMAP (Internet Message Access Protocol) allows users to access and manage their email directly on the server. This means that when emails are read or organized, those changes are reflected across all devices that access the account. IMAP is designed for users who need to access their email from multiple devices, as it keeps the emails stored on the server, allowing for synchronized access.

In contrast to this, POP3 (Post Office Protocol version 3) typically downloads emails from the server to a client device and often deletes them from the server after retrieval, unless configured otherwise. This fundamental difference caters to various user needs: IMAP is ideal for individuals who use more than one device to check their email, while POP3 works better for those who primarily use one device and want to manage their emails offline.

The ability to automatically sync emails across devices and maintaining a copy of the emails on the server is a key feature of IMAP, making it suitable for modern email usage.