New figures from ComReg show that An Post delivered 85% of standard mail throughout the country within one working day during the first three months of this year.
This is a one percentage point improvement on its service quality performance over the same time last year but still falls short of the company's target of 94%.
The Commission for Communications Regulation says that 98% of mail was delivered within three working days. An Post's target is 99.5%.
ComReg said the first quarter performance for next day delivery has not improved on the 2010 annual result and so the 'significant deficit' remains between the company's current performance and its target of 94%.
