(a) Notices, orders, answers and other papers may be served personally, by mail, or electronically, as provided in an operational bulletin issued pursuant to section 2527.11 of this Title. Except as otherwise provided by section 2529.2 or Part 2531 of this Title, when service, other than by the DHCR, is made personally or by mail, a contemporaneous affidavit providing dispositive facts by the person making the service or mailing shall constitute sufficient proof of service. When service is by registered or certified mail, the stamped post office receipt shall constitute sufficient proof of service. Once sufficient proof of service has been submitted to the DHCR, the burden of proving nonreceipt shall be on the party denying receipt.

(b) Where a notice of appearance has been filed by an attorney, in accordance with section 2523.6 of this Title, service on the attorney shall be deemed proper service as if made on the party or parties represented.

(c) Unless otherwise expressly provided in this Part, no additional time is required for service by mail of any notice, order, answer, lease offer or other papers, beyond the time period set forth in this Part and such time period provided is inclusive of the time for mailing.

(d) Unless otherwise expressly provided in this Part, no additional time is required to respond or to take any action when served by mail with any notice, order, answer, lease offer, or other papers, beyond the time period set forth in this Part and the time to respond is commenced upon mailing of said notice, order, answer, lease offer or other paper.