From:
https://www.vodafone.co.nz/email/
What you need to know
From 21 August 2019, we’re closing our email service. This means your email address will stop working and you won’t be able to send or receive emails with it.
Since we launched our email service almost 20 years ago, email functionality has come a long way. We know our email service is no longer delivering the sort of experience that Kiwis need, which is why we are closing this service.
We’re really sorry for the inconvenience, but we genuinely believe this is the right decision to ensure you stay connected now and in the future.
So if I understand this correctly, the e-mail addresses will be 100% closed, login will be deactivated and any e-mails sent to them will bounce.