def checkout_and_get_mail(self, *items):
        mailing = Mailing(self.portal)
        for item in items:
            checkout.visit_checkout_with_one_item_in_cart(item)
        checkout.goto(checkout.ORDER_REVIEW).finish()

        mails_by_recipient = mailing.get_messages_by_recipient()
        owner = 'Shop Owner <*****@*****.**>'
        self.assertIn(owner, mails_by_recipient,
                      'Expected a mail to the shop owner to be sent')
        return email.message_from_string(mails_by_recipient[owner][0])