Section 9. If the person who delivers or forwards a process to an officer for service requests him to return it by mail or express, compensation shall not be allowed for more than twenty miles’ travel in the service, unless the officer actually and necessarily travels more than that distance in serving the same, exclusive of travel from the place of service to the place of return, and an officer in such case, who properly directs such process to the place of return and sends it by mail, postage prepaid, or delivers it to an express company, shall not be liable for damages if it fails to reach its destination.