> With IMAP, when an email gets deleted by some client, other clients will also delete their local copies of that email. That won't happen with POP3.

This is not an IMAP feature, this is a client feature. There are plenty of clients that don’t sync deletes, if you don’t want to.

Or, just don’t delete your emails? If you delete a POP email from your client, it’s also gone for good.