Realestate.co.nz doesn't offer a self-service option for changing your enquiry email address, so the change is made by their support team. This article explains what to do.
Before you start, you'll need your Leads email address. See Leads: Finding Your Leads Email Address.
Requesting the Change
Get in touch with Realestate.co.nz Support directly and provide them with the relevant email address (or addresses) so they can update where your enquiries are sent.
After Setup
Once the change is made, force a re-feed of the agent's (or agency's) listings so the new Leads address is sent through. See Portals & Publication: How do I Force Upload Multiple Listings?.