Glen,
Unfortunately, the protocol (SMTP) used to send e-mail does not support such
a command. The only receipt you can guarantee to receive is a delivery
receipt. Due to different software platforms, not all commands are honoured
between mail servers. You can generate an READ RECEIPT, only if the your
mail client and destination mail server supports this option.
If you are on the same network, for example, your business, you can use
Microsoft Exchange Server which supports this and many other features if
recipients work from the same mail server.
To find out more on generating READ & DELIVERY receipts, open your e-mail
client and go to the help section - do a search for 'receipts'.
To find out more about Exchange Server,
http://www.microsoft.com/exchange
Hope this information helps.
Peter Batten