If you pay some amount (eg. Rs. 1000) to the Postal Department in India, they will assign you a Post Box number. Then you can provide your Post Box number to all. All the letters addressed to the Post Box number will be kept there. You should go and collect the letters whenever you want.

The number of a letter box at the post office where mail is collected

The number of the box (slot) the post office puts your mail in, if you live in a tiny town without home mail delivery or you pay extra for a box for whatever reason (often home based business)

Paid service of postal department; which gives a number to your letter box for better delivery of postal letters parcels etc.