What generally happens to emails with POP3 when they are accessed by a client?

Emails accessed via POP3 (Post Office Protocol version 3) are typically downloaded to the client device and often deleted from the server. This protocol is designed for users who want to obtain their emails for local access, primarily focusing on a single device. When an email client uses POP3 to retrieve messages, the standard behavior is to download the entire message to the user's device and then remove it from the server.

This approach contrasts with protocols like IMAP (Internet Message Access Protocol), which allows for synchronization and keeps emails on the server, enabling access from multiple devices. In the case of POP3, once the emails have been downloaded, they are no longer available on the server, effectively clearing space and ensuring that the user manages their messages locally. Hence, the correct understanding of how POP3 operates is that emails are indeed downloaded to the client and deleted from the server.