I received a confirmation email as an administrator regarding the booking, but I did not receive a booking confirmation as a customer.  I used the Email test tool provided with the plugin, but there were no logs.  I checked the spam folder in Gmail; still nothing.
My web hosting site currently hosts a few websites.  If I use the email address as a customer from any of the website's emails, it works.  If I try to use a Gmail account, it fails.  No emails were sent.  Any idea what's happening?