An IdSMTP message is ALWAYS demanding a response from Sender??

From: Anton Feiertag (anton_at_dokker.com)
Date: 12/22/03 

Date: Mon, 22 Dec 2003 13:43:23 +0200

Hi All

I am sending a message with IdSMTP (to myself). When I open the message it
is always poping up with a message "The Sender has requested a response that
you have received the message. Do you want to send a receipt?"

How can I disable this popup.

Thanks
Anton Feiertag