"Parcels posted to and from rural areas already incur extra costs, and we would not wish to see further targeting of rural customers who are so dependent on the mail service."
"Rural delivery service is a real lifeline for many people."
She said the changes would unfairly disadvantage rural businesses who need a rapid service for mail-order food at a reasonable cost, both to the supplier and the customer.
"Rural Women New Zealand actively supports and promotes such businesses and we need to be satisfied that the proposed NZ Post changes will not have a negative impact on rural enterprise and innovation."
Mrs Evans said for some living in remote areas, the rural delivery contractor is the only contact with the outside world for days at a time.
She said members mentioned how important contact with the rural delivery contractor was in combating loneliness, which can lead to depression - another very real problem.
Rural Women NZ will be further consulting with its members on the NZ Post proposals and making a formal submission.
NZ Post spokesman John Tulloch said it welcomed submissions from the rural sector, which would "help design the solution".
"We're fully aware of their concerns and we're very committed to engaging with them, but first and foremost let's let the process go, so we welcome, and the Government will welcome, their submissions ... and we'll be engaging closely with them."
He also said NZ Post would work with businesses who relied on mail deliveries to create a postal design which worked for them.
"If we went to a guaranteed minimum of say three days and we got to that point where we actually vote that, [businesses would] be paying a premium if they wanted it any more frequent," he said.
About 20 per cent of the sending customers made up 80 per cent of letter mail, he said.
"One of the first things we would look to do, for our big premium sending customers anyway, is to work with them about design."
He said it was too early to say how the proposed change would impact on PO Box mail.
"They do fall under the definition of a delivery point ... but it would be preemptive to say if we got the flexibility in the deed, what the design of the delivery network would be and how that would impact on PO Boxes."
The proposed change was a guaranteed minimum which did not mean that was what it would be for a PO Box, he said.
When asked if delivery days would be increased at peak times, such as Christmas, Mr Tulloch said: "The standard letter delivery timeframe is up to three working days, so it's not necessarily next day.
"The system takes up to three working days for the letter to be delivered so if you change delivery frequency that shouldn't necessarily impact on where we currently are."