NEVER USE THIS ON PRODUCTION SITES – DEVELOPMENT/TESTING ONLY

what it does:
if defined, it will show you the output of all emails that would/will have been sent on completion of orders including recipients etc on the frontend.

You might want to consider using this in conjunction with wppizza-tools->” Disable email sending”.

Really only useful for testing/development purposes.
WILL ALSO ONLY WORK WITH CASH ON DELIVERY ORDERS / TESTS AND NOT NECESSARILY WITH ALL BROWSERS (chrome/safari i believe should work, though there may be others)

affects:
frontend

usable:
anytime, can also be deleted again at any time.

example:

define('WPPIZZA_VIEW_EMAIL_OUTPUT',true);/*bool*/

where to add/define:

in your wp-config.php before:
/* That's all, stop editing! Happy blogging. */

Disclaimer:
As with all filters, actions and constants:
Although these should be safe to use as indicated, there are no guarantees. Use at your own risk. Make backups before usage.