Unless otherwise specified by the Associate Director 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 Associate Director 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 Associate Director or Director; or

(b) Any of the following methods if a respondent demonstrates electronic filing is not practicable and the Associate Director 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.