§ 307. Personal service upon the state. 1. Personal service upon the state shall be made by delivering the summons to an assistant attorney-general at an office of the attorney-general or to the attorney-general within the state. 2. Personal service on a state officer sued solely in an official capacity or state agency, which shall be required to obtain personal jurisdiction over such an officer or agency, shall be made by (1) delivering the summons to such officer or to the chief executive officer of such agency or to a person designated by such chief executive officer to receive service, or (2) by mailing the summons by certified mail, return receipt requested, to such officer or to the chief executive officer of such agency, and by personal service upon the state in the manner provided by subdivision one of this section. Service by certified mail shall not be complete until the summons is received in a principal office of the agency and until personal service upon the state in the manner provided by subdivision one of this section is completed. For purposes of this subdivision, the term "principal office of the agency" shall mean the location at which the office of the chief executive officer of the agency is generally located. Service by certified mail shall not be effective unless the front of the envelope bears the legend "URGENT LEGAL MAIL" in capital letters. The chief executive officer of every such agency shall designate at least one person, in addition to himself or herself, to accept personal service on behalf of the agency. For purposes of this subdivision the term state agency shall be deemed to refer to any agency, board, bureau, commission, division, tribunal or other entity which constitutes the state for purposes of service under subdivision one of this section.