(2) Service of any summons, notice, order, document, process, information or written statement to be served on an international limited partnership formed pursuant to this Act may be proved by showing that the summons, notice, order, document, process, information or written statement —
-
(a) was mailed in such time as to admit its being delivered in the normal course of delivery, within the period prescribed for service; and
-
(b) was correctly addressed and the postage was prepaid.