Section 21: Service of notice

(1) Any notice required or authorised by or under this part of this Act, to be served on
any person may be served either-
(a) by delivering it to the person concerned; or
(b) by leaving it at his proper address; or
(c) by post and addressed to the person at his principal office, however, where a notice is served by post otherwise than in registered letter, service shall not be deemed to have been effected, if it is proved that the notice was not received by the person to whom it was addressed.
(2) Any notice required or authorised to be served upon a body corporate shall be deemed to have been duly served if it is served on the secretary to the body corporate.
(3) For the purposes of this section, the proper address of any person on whom such a
notice as aforesaid is to be served shall-
(a) in the case of the secretary of a body corporate, be that of the registered or
principal office of the body corporate; and
(b) in any other case, be the last known address of the person to be served.
(4) Where the name of a person carrying on an air transport undertaking at any premises
is not known then, if any such notice as aforesaid is sent by post in a registered letter
so addressed as to show the name in which and the premises at which the undertaking is
carried on, the letter shall be deemed for the purpose of this section to be properly addressed.