Third party access to postal networks can be made subject to a range of access conditions. While the pricing of postal network access has received much research attention, the effects of access on quality of service have received less. Using data on international postal services in a large panel of European countries, we estimate an econometric model of average time-to-delivery for letter post, including a range of access conditions. We find that several access conditions have a significant association with service quality. Appropriate access conditions may improve service quality.