An Post has told regulators it plans to cut jobs by the equivalent of 1,500 full-time positions.
It also wants a price increase and warns about the dangers of too much competition for the State-owned company.
The group says it will reduce its workforce between this year and 2016. The cuts will bring the total number of reductions to 2,600 since 2008.
The company says price increases form a "critical component" of plans over the next five years.
It says: "European counterparts have recently made at least one price change, leaving Ireland as the second lowest basic tariff across the EU15 group of countries."
An Post has applied for a 10% increase on regular stamps from 55c to 65c. ComReg has not yet made a decision on the request.
In a submission to ComReg, An Post raises issues with allowing more competition to the State-owned postal company.
An Post says a regime aimed at encouraging as many operators as possible "may have unintended consequences...it may have the perverse effect of undermining the survival of more viable and long established players."
The company also raises questions about ComReg's costs and said it is important that is shows it can operate "in an efficient manner".
In its Postal Strategy Statement to 2014, ComReg says that declining mail volumes are in danger of producing an uncontrollable spiral of rising unit costs leading to higher prices and a greater decline in mail.
Between now and the end of 2014, ComReg wants to make sure that a universal postal service is available, and to promote the interests of postal service users.
ComReg says it is now more important than ever for postal services to stay competitive, cost effective, innovative, and to aligning their postal services to users' needs.