Good day, please check out this Delphi tutorial that utilizes the Clever POP3 Server component together with the POP3 File Handler component to deliver Emails to clients from your own application.div>
The program shows how to override the default POP3 command handlers and implement your own ones. Please check out the STAT and the LIST overrides. Comments within the source code will help you to understand how the code works.
The sources are available on GitHub