Just received this email this morning:

" Hi,
You have GST returns due in 3 days up to $373.20 NZ for late ( 2016/2017 ).
To ensure you meet your tax obligations and get the full refund, check the customer refund form at : IRD_Refund_Form

Thanks,
The Customer Services Team"

I am pretty sure this is spam email as I am too old to register for GST, but just to re-confirm that I am not too old to be fooled by them.