The summons shall be served on the respondent forthwith after it is issued by sending it by first class post to his last known address; and the date of service shall, unless the contrary is shown, be deemed to be the 7th day next following that on which the summons was posted.

Where any process or order of the court or other documents is required under proceedings subject to these Rules to be served on any person who is not in Northern Ireland, the court may order service on him of that process or order or other document to be effected within such time and in such manner as it thinks fit, and may also require such proof of service as it thinks fit.