Section 21(7) in The Rajasthan Lands Special Irrigation Charges Rules, 1954
(7)When a summons, notice, order or requisition is so forwarded and it is proved that the letter was properly addressed and duly posted and registered, the officer having authority to issue or make the same may presume that it was served, delivered or communicated at the time when the letter would be delivered in the ordinary course of post.
