The checkout wizard is not reentrant, if you need to run the checkout wizard again, you will need to delete the pages that where created the first time:
checkout.php
confirm.php
checkout_success.php
checkout_failure.php
pp_confirm.php
pp_checkout_success.php
pp_checkout_failure.php
some of these pages may not be created, they depend on the settings you use in the checkout wizard.
the option to create an email receipt using Universal Email will only be available if you are using a local checkout method, if you select to use a remote checkout method, the gateway will handle sending the receipt.
