The Reserve Bank of New Zealand last night would not comment on the cause of an email outage that affected the operation of the country's real time gross settlements system on Monday afternoon.
However, a spokesperson for the central bank last night downplayed the impact of the outage, insisting that it did not impact any settlements.
"We experienced an issue earlier today which affected incoming emails into RBNZ's RTGSHelpdesk and NZClear," the spokesperson said.
"There was no impact on the ESAS-NZClear infrastructure and the system remained open and operational all day.
"The backlog was cleared by early afternoon and did not impact any settlements."
Banks and other participants using the country's ESAS system were notified on Monday afternoon of an outage affecting an email service used for communicating instructions to the central bank.
ESAS is New Zealand's main high value payments system used to settle payments instructions between banks that subscribe to the service. The Kiwi arms of Australia's four major banks account for most of the system's transaction volumes.
A mid-afternoon notification issued by the RBNZ advised banks to fax instructions to the RBNZ while the email outage was addressed.
"We are currently experiencing an issue with our mail server which we are investigating with urgency," the RBNZ told RTGS participants.
"If you have any instructions for ESAS-NZClear, can we please ask that you fax these through."
About an hour later the RBNZ issued a second notification informing participant banks that the email problem had been resolved but that it had a backlog of instructions to work through.
"The recent email issue has now been resolved and all emails are flowing as expected," the RBNZ said.
"Please note that we do have a backlog of requests that require processing, so please bear with us whilst we work our way through these."
The RBNZ did not give any details on the cause of the outage.
Central banks around the world are spending much time and money trying to strengthen their high value settlement platforms against hacking threats, although systems operating in developing economies are seen as most at risk.
A seizing of Uganda's real time gross settlement service in July triggered heavy speculation in that country's media that the outage had been caused by hackers.
The Kiwi central bank is in the process of transitioning to a replacement ESAS platform by the end of February next year.
The results of a customer survey published in the ESAS 2019 annual report indicate there was a decline in customer satisfaction with the platform last year, with 5 per cent of respondents saying its operation did not meet expectations.
This was the first time since at least 2014 that any respondents said the system did not meet expectations.
In January this year the availability of the ESAS service was impeded when a faulty computer disk slowed the processing of settlements.
The RBNZ aims to have its high value transaction service available 99.9 per cent of the time in any year.