(a) Complaint. The complaint or a copy thereof may be served upon the respondent by certified mail, or first-class mail as hereinafter provided, by delivering it to the respondent, or the respondent's attorney or agent of record either in person or by leaving it at the office or place of business of the respondent, the attorney or agent, or in any other manner which may have been agreed to in writing by the respondent. Where the service is by certified mail, the return post office receipt signed by or on behalf of the respondent shall be proof of service. If the certified matter is not claimed or accepted by the respondent and is returned undelivered, complete service may be made upon the respondent by mailing the complaint to him/her by first-class mail, addressed to the respondent at the last address known to the Executive Director. If service is made upon the respondent or his/her attorney or agent in person or by leaving the complaint at the office or place of business of the respondent, attorney, or agent, the verified return by the person making service, setting forth the manner of service, shall be proof of such service.
(b) Service of papers other than complaint. Any paper other than the complaint may be served upon the respondent as provided in paragraph (a) of this section or by mailing the paper by first-class mail to the respondent at the last address known to the Executive Director or by mailing the paper by first-class mail to the respondent's attorney or agent. Such mailing shall constitute complete service. Notices may also be served upon the respond- ent or his/her attorney or agent by telegraph.
(c) Filing of papers. Whenever the filing of a paper is required or permitted in connection with a suspension or termination proceeding, and the place of filing is not specified by this subpart or by rule or order of the Administrative Law Judge, the paper shall be filed with the Executive Director of the Joint Board for the Enrollment of Actuaries, Treasury Department, Washington, D.C. 20220. All papers shall be filed in duplicate.