Gujarat High Court Civil Manual (subordinate court practice), 1960
(a) A summons should be sent by registered post and if the defendant does not appear or is not represented, proof should be given (i) that at the time of the service the defendant ordinarily resided and was actually residing at the foreign place in question, and (ii) that a cover correctly addressed to him, containing the summons was posted, the postal acknowledgment being produced or annexed to the affidavit. (b) Service by post while necessarily confined to cases where there exists postal communication between the place where the Court is situate and the place in which the person to be served resides, will in practice cover the great majority of cases and resort is not to be had to any other method for service upon persons outside India save for sufficient reason. (c) The principle is that though there are other methods of service, e.g., through official channels, the Code does not require service outside India to be made through official channels