People will have to use Port Erin or Castletown
Port St Mary post office will close its doors at the end of this month.
The Isle of Man Post Office says it's received no expressions of interest to provide the service which is run from the newsagents.
The current sub postmaster will terminate his contract on 29 October.
From November 1 people will have to travel to Port Erin or Castletown to undertake their postal business.
A statement from Isle of Man Post Office says: "In an increasingly digital world, as customers increasingly choose digital alternatives to counter-based services, the migration of counter service users from Port St Mary will make Port Erin Post Office a stronger and more sustainable office for all customers, commercial partners and the sub postmaster."