Any time I try emailing anything NZ government related/associated (councils, schools etc), my emails fail with a SPF failure. Diagnostic-Code: smtp; 550 SPF Sender Invalid - envelope rejected

Yet appears to work to send to anyone/anywhere else.

My SPF has been in place for a number of years and never caused any issues, only change recently was I moved mail provider, and updated relevant record.

v=spf1 mx a ip4:103.121.34.8 a:mail.xpd.co.nz -all  is what I'm using.

Am i missing something ?