Unless otherwise specified by the recommending official or Director, a respondent shall file the response and any other paper with the Executive Secretary at the mailing or electronic address provided by the Bureau, and the initiating official, recommending official, and Director shall serve any paper, other than a Notice as set forth in § 1091.104, on a respondent, by:

(a) Electronic transmission upon any condition specified by the recommending official or Director; or

(b) Any of the following methods if a respondent demonstrates electronic filing is not practicable and the recommending official or Director permits:

(1) Personal delivery;

(2) Delivery through a reliable commercial courier service or overnight delivery service; or

(3) Mailing the papers by U.S. Postal Service First Class, Registered, Certified, or Express Mail.