RAWMARSH post office is closed until further notice, due to flooding from burst water pipes early on December 29.
The Bellows Road shop was flooded from an empty unit above.
Customers are being re-directed to Monkwood Post Office at Rawmarsh or the main Rotherham Post Office.
A Post Office spokesman said: “There is a considerable amount of damage at Rawmarsh and we don’t expect to be re-opening in the very near future. We will keep people informed”.
Postmaster Jim Wildsmith added: “I lost a substantial amount of stock and the computers may be affected. We serve a lot of pensioners here, and I’m sorry they have been let down”.