Federated Farmers say the proposed cuts to mail delivery will have a huge impact on rural New Zealand.
New Zealand Post wants to cut the number of days it is required to deliver mail to most addresses from six to three days a week and replace some postal outlets with self-service kiosks to cope with falling mail volumes.
It says 265 million fewer items were posted last year compared with 2002.
Federated Farmers national president Bruce Wills says some of its members live in areas with no internet access or cellphone coverage.
"We just have to be pretty cognisant of the fact that it is for a lot of rural folk the only reliable communication they have. We still have lots of areas of New Zealand where cellphone coverage frankly doesn't work."
Mr Wills says while the change seems inevitable, it wants to work with the postal service to make sure that any changes work for everyone.
The Government has acknowledged that rural communities are likely to be hardest-hit by the proposal.
Communications and Information Technology Minister Amy Adams is seeking public feedback on the plan.
Ms Adams says some of the most remote areas are receiving mail only one, two or three days a week at present.
However, she says rural areas are of particular concern for the Government and it recognises that access to broadband is not as good as in the cities.
Reduced deliveries are part of what New Zealand Post believes it needs to do in order to maintain a sustainable service, she says.