Nothing in this title shall be construed to prohibit any express company from hauling or carrying free of charge any package or property of its actual bona fide officers, attorneys, agents and employees while in the service of such express company, nor to prevent any article being sent free to any orphan home or other charitable institution, nor to prohibit any telegraph or telephone company from transmitting free of charge any message of its bona fide officers, attorneys, agents or employees and their families while in the actual employment of such company or its receiver or lessee; provided the actual bona fide officers and employees upon annual salaries of railway telephone companies and telegraph companies are hereby permitted to exchange frank privileges and free transportation over their respective lines of railway and telegraph or telephone.