under a common name shall be served by delivering a copy of the petition to its service agent, if one has been so designated. (B) Manner of Service (i) Service by nondigital means Service by nondigital means may be any of the following: (I) Personal, including delivery to a responsible person at the office of counsel. (II) By priority mail. (III) By third-party commercial carrier for delivery within 3 days. (ii) Service by digital means Service of a paper may be made by sending it by any digital means, including through a provider's designated reporting system. (iii) When service is completed Service by mail or by commercial carrier is complete 3 days after the mailing or delivery to the carrier. Service by digital means is complete on filing or sending, unless the party making service is notified that the paper was not received by the party served. (C) Proof of service A petition filed under paragraph (1) or (2) shall contain— (i) an acknowledgment of service by the person served