O.K. I managed to get the local checkout working where is captures the correct email address of the customer. I just needed to "tighten up" the code on confirm.php page.
However, I am having a new problem as the PayPal Express Checkout Button does not work. The button has been placed on a secondary checkout page and not checkout.php. Clicking the PayPal Express Checkout Button results in being taken to the checkout_failure.php with an error code 10727. The detailed error message is "There's an error with this transaction. Please enter an address1 in the shipping address."
Any suggestions on how to get the PayPal button working?