NZ Post is set to cut 750 jobs over the next five years from its workforce of 4500 employees as mail volume continues to decline.
Chief executive David Walsh said New Zealanders have drastically changed the way they choose to communicate.
"New Zealanders are choosing to communicate more and more online, and as a result of that, unfortunately it has an impact on the mail business."
Online shopping and increases in parcel delivery have not offset the lack of things like bank statements, he told RNZ's Midday Report, and other "things hat used to come through the mail" but were no longer needed.
"Ten years ago households got about 12 items a week - now [it's] less than two."
Twenty years ago, New Zealanders sent more than 1 billion mail items a year - but this has decreased dramatically to around 220 million.
"Mail decline isn't unique to New Zealand. Postal services around the globe are responding to the same changes in communication and are focusing on the challenge of maintaining a service that has high operating costs and very low usage," Walsh earlier said in a statement.
"We will soon begin consultation with a view to reducing the number of roles involved in mail as a response to continuing mail decline. This change will not happen overnight. This will be an adjustment that we will make gradually over the next five years. Our focus will be on our people and supporting them with this transition."
NZ Post predicted mail would further decrease to about 120 million items by 2028.
Over the last 10 years the mail provider has made several changes to tackle high costs, including cutting down mail delivery in urban areas from six to three times a week, increasing prices and consolidating delivery branches.
"The same technology that's causing a decline in the number of letters being sent, has led to growth in online shopping," Walsh said. "NZ Post is uniquely positioned to capture growth in ecommerce and we are continuing to invest in our parcel processing capacity."
Walsh told Midday Report rural customers would not be forgotten, and see "almost no change" to the services NZ Post already offered.
Consultation on the cuts was to begin soon. Walsh said the business had already made a lot of changes to adapt, including recently closing a depot in Manawatū.
Walsh said NZ Post would "trial a whole range of things" to figure out what worked best, including part-time work in some areas, or delivering different kinds of items - such as parcels and letters - on different days.
There were no plans yet to reduce the number of days deliveries were made, the deed of understanding NZ Post has with the government requiring at least three a week.
Walsh said the cost of delivering a letter would likely soon hit $2, up from $1.50, which he said was a "good price".
Elderly, rural communities will feel the impact, community leaders say
The losses have frustrated the Postal Workers Union, which was concerned about the organisation failing to put the needs of the country first.
National co-president John Maynard said he understood the decline but the slow disappearance of postal boxes was causing a headache for communities.
"People will go to the posties sometimes and say do you mind taking my letter for posting because I can't find a posting box or it's too far away so the elderly people or the people without much transport, they're quite seriously affected by fewer places to post their letters and sometimes irregular mail delivery coming to them," Maynard said.
The price of postage will also increase an extra 30 cents up to $2 in July - a move to help curb high costs for NZ Post.
Grey Power vice president Pete Matcham was worried about the impact on the elderly community.
Matcham said half of elderly people over the age of 75 rely on the postal service as a lifeline.
"Around 50 percent will use post of preference, even if they have the opportunity and ability to use the internet. With the cost of living the way it is at the moment, they just don't have any spare cash at all. What is a small increase to many people can make a major difference to them," he said.
The impact was felt even more by elderly living in rural areas where the post was sent out less frequently, he said.
The feeling of isolation was mutual with the rest of the rural community because of connectivity in these areas.
Rural Women New Zealand chief executive Gabrielle O'Brien was worried the job cuts could mean her organisation will struggle to get to the people that need them.
"If we are sending out information to them and we need to send it by post, that increases our costs as well. There is always the potential that will lead to less services available to people, less publications, or less communication," O'Brien said.
E tū negotiation specialist Joe Gallagher sadi the union was helping workers through a transitional agreement of getting new jobs.
"We just need to work through what their individual needs are so that we taylor their approach to what they want and go from there. We've run a few of these processes now and it's the best, fairest and most transparent way to get the best outcomes for workers moving forward," Gallagher said.