write a formal letter to a postman informing him of your change of address.
30 September, 20xx.
Subject: Change of postal address
This is to inform you of the change in the postal address of the company headquarters of ABC company from 21, Tughlaq Road, New Delhi to 34, Shahjahan Road, New Delhi with effect from 5 October, 20xx. You are requested to redirect any mail posted to the previous address.
CEO, (ABC company)