Section 90. Every document to be served by post on the Company shall be posted in such time as to admit of its b

90. Every document to be served by post on the Company shall be posted in such time as to admit of its being delivered in the due course of delivery within the period (if any) prescribed for the service thereof; and, in proving service of such document, it shall be sufficient to prove that such document was properly directed, and that it was put as a registered letter into the post office. Authentication of notices by Company.