pop3d question

[Leon Vismer]

Hi,   I was wondering if their was an available extension or way to make qmail-pop3d send mail back to a mail sender after a specific user has checked his mail.   I.o.w if leon send mail to john, that when john comes and checks mail it mails leon with a message to confirm that john has actually logged in to check his mail.   Thanks in advance for your responce   Leon Vismer