Customers in these areas have been told to not use post-boxes during the work stoppage...
No mail will be delivered in Dublin 6 today as An Post workers have engaged in unofficial strike action.
"As a result of the staff refusing to carry out their normal work, it is not possible to provide a mail collection service for Dublin 6 customers at the delivery unit," An Post said.
The affected areas include Rathmines, Rathgar, Ranelagh and parts of Terenure.
It advises people not to use post-boxes as mail collections today could be impacted by the work stoppage.
"An Post urges the staff involved to cease this disruption to customers by returning to normal working and allowing any issues to be dealt with through the established industrial relations procedures for handling workplace grievances," a statement from the state-owned service provider continued.
An Post said that it is working with the Communications Workers Union (CWU) to resolve this issue.
The union confirmed to Newstalk that it is speaking with An Post.
The CWU also said that it has "directed members to continue to work normally to enable the underlying issues, which were the cause of the disruption and concern to members, to be addressed fully and as expeditiously as possible."