(1)Save as otherwise provided by these rules or by an order of Court, all notices, summonses, and other documents required to be served on any person, may be served either personally by delivering a copy thereof to such person or upon his advocate where he appears by advocate or, except where personal service is required by prepaid registered post for acknowledgment due addressed to the last known address of such person. In the case of service by registered post where no acknowledgment signed by the addressee or his duly authorised agent is received, orders of Court shall be obtained as to the sufficiency of service or as to the further steps to be taken for service as the Court may direct :Provided that where a notice, summons or other document has to be served on any class of persons such as shareholders, debenture-holders, creditors and the like, the same may be sent by prepaid registered post or by ordinary post under certificate of posting, as may be provided by these rules or by an order of Court, and unless otherwise ordered by the Court, the service shall be deemed to be effected at the time when the said notice, summons or other document ought to be delivered in the ordinary course of post by the post office, and notwithstanding the same is returned undelivered by the post office.
