Postal deliveries have been suspended at a housing estate in Tallaght.
An Post says the decision was taken as a last resort, following ongoing threats to its staff.
People living in the Mac Uilliam Estate will have to collect their post until further notice.
An Post has blamed "a number of incidents involving threats to the safety and security of staff".
It says it has "a clear duty of care to our staff and cannot allow a situation where our staff are put at risk in any way".
Affected customers have been informed, and have been given details of the alternatives put in place.
Local TD Sean Crowe believes only a small number of people are to blame.
"This is a serious development that requires a Garda response.
I met with the authorities today, and they agreed to meet up with An Post to try and resolve the safety issues", he said.
An Post says it rarely refuses to deliver post, and only ever does so as a last resort.
Residents can pick up their mail at An Post’s Dublin 24 Delivery Service Unit,
That is based at Unit 5, Square Industrial Complex, Dublin 24 D24 W68E.
