code: def get_raw_email(self):
          
          if 'email' in self.payload:
              raw_email = email.message_from_string(self.payload['email'])
              return raw_email
          else:
              return None
docs: This only applies to raw payloads:
          https://sendgrid.com/docs/Classroom/Basics/Inbound_Parse_Webhook/setting_up_the_inbound_parse_webhook.html#-Raw-Parameters