Dear Beverly,
Go to Tools --> Accounts and double-click on the name of the account you'd
like to modify). Then, on the Edit Account pane that pops up, select the
Options tab. You will see a table marked "Additional headers:" Make a new
entry there like this: under Header, type: "Disposition-Notification-To:"
(without the quotation marks), then, on the same row but in the Value field,
enter the e-mail address to which you want the return receipts to go.
The problem with this is that it attaches return receipt requests to every
outgoing message. My solution to that is to create two "accounts" that use
identical settings except for this one additional header; then, I chose to
send from either account based on whether I want a return receipt or not.
This works well esp. because Entourage provides a nifty drop-down menu to
select which account you want to use when composing a message.
-Sam