Authorize payment email could be send to guest user

Always send the email to the order.email value

app/mailers/payment_mailer.rb

@@ -8,9 +8,7 @@ class PaymentMailer < Spree::BaseMailer
     subject = I18n.t('spree.payment_mailer.authorize_payment.subject',
                      distributor: @payment.order.distributor.name)
     I18n.with_locale valid_locale(@payment.order.user) do
-      mail(to: payment.order.user.email,
-           from: from_address,
-           subject: subject)
+      mail(to: payment.order.email, from: from_address, subject: subject)
     end
   end