(a) An applicant, any other party to a proceeding, or a person filing a protest shall serve a copy of all documents filed with FE upon all parties unless otherwise provided in this part. The copy of a document served upon parties shall be a true copy of the document filed with FE, but does not have to be a copy stamped with the time and date of receipt by FE. The FE shall maintain an official service list for each proceeding which shall be provided upon request.

(b) When the parties are not known, such as during the initial comment period following publication of the notice of application, service requirements under paragraph (a) of this section may be met by serving a copy of all documents on the applicant and on FE for inclusion in the FE docket in the proceeding.

(c) All documents required to be served under this part may be served by hand, certified mail, registered mail, or regular mail. It shall be the responsibility of the serving party to ensure that service is effected in a timely manner. Service is deemed complete upon delivery or upon mailing, whichever occurs first.

(d) Service upon a person's duly authorized representatives on the official service list shall constitute service upon that person.

(e) All FE orders, notices, or other FE documents shall be served on the parties by FE either by hand, registered mail, certified mail, or regular mail, except as otherwise provided in this part.