Next-day delivery of standard mail by An Post was unchanged at 78% in the three months to June, still falling short of targets set by the regulator.
Results from the independent quarterly report on the quality of service performance from regulator ComReg found that 78% of single piece priority mail was delivered within one working day throughout the State, against a target of 94%.
The statistics also showed that 98% of all mail was delivered within three working days, also unchanged from the previous three months, and just below the 99.5% target set by ComReg.
However, the figures show that mail posted locally outside of Dublin for local delivery recorded an unusually lower performance of 77% next day delivery.
This compared to a success rate of 81% for the first three months of this year.
81% of mail posted in Dublin for local delivery was posted the next working day, the report showed.