(a) A registration, an activity report, or a non-registrant disclosure statement filed by first-class United States mail or by common or contract carrier is timely if:
(1) it is properly addressed with postage and handling charges prepaid;
(2) it bears a post office cancellation mark or a receipt mark from a common or contract carrier indicating a time within the applicable filing period or before the applicable filing deadline, or the person required to file furnishes satisfactory proof that it was deposited in the mail or with a common or contract carrier within that filing period or before that filing deadline; and
(3) it was in fact received by the city secretary.