New Zealand Post has revealed that total mail volumes slumped more than 8 per cent, a drop of 35 million items in the past six months, compared with a year ago.
NZ Post posted an after tax profit of $59.6 million for the half year to the end of December, up from $35.4 million in the corresponding period in 2011.
The profit was boosted by Kiwibank and the group's financial services businesses.
But NZ Post chief executive Brian Roche said "challenges remain for the mail business".
Tight cost management helped offset the declines in revenue, he said.
"Thirty five million fewer pieces of mail.. is a stark reminder of the need to change," Roche said.
NZ Post was confident it could maintain a "viable and sustainable" mail network if it was given the flexibility to make the changes it needed to.
The changes could be made in a "measured and planned" manner, in the best interests of the community and business.
But the latest mail volume figures showed they needed to make decisions now, rather than putting it off.
During the half year, NZ Post sold its shareholding in Datacom which would result in a one off gain on sale.
It had also sold two buildings in Auckland and Wellington.
All of that would free up capital for both the bank and continued changes in the logistics and mail business.
During the half year, NZ Post took full control of the courier business, Express Couriers, buying the balance of 50 per cent in June last year.
For the half year to the end of December 2012, NZ Post recorded revenues of $872.3 million, up from $670.2m in the same period the year before.