Section 37. Every order of the department shall be served upon every person or corporation to be affected thereby, either by personal delivery of a certified copy thereof, or by mailing a certified copy thereof, in a sealed package, postage prepaid, to the person to be affected thereby or, in the case of a corporation, to any officer or agent thereof upon whom a summons may be served under the laws of the commonwealth. Every person and corporation shall notify the department forthwith, in writing, of the receipt of the certified copy of every order so served, and in the case of a corporation such notification shall be signed and acknowledged by a person or officer duly authorized by the corporation to admit such service. Within a time specified in the order, every person and corporation upon whom it is served shall, if so required in the order, notify the department in like manner whether the terms of the order are accepted and will be obeyed. Every such order shall take effect at a time therein specified and shall continue in force either for a period designated therein or until changed or abrogated by the department.