Hi Pauline,
Our article about typing Host Name=@ is to make sure the domain could be verified. Sometimes it is unavailable by some domain registers or domain hosts. Based on this situation, I suggest you contact Melbourne IT support to help you create the correct record.
I believe it will be beneficial to others who encounter the similar issue if you could share the solution about your situation. If there is more assistance needed here, please feel free to post here.
Thanks,
Maggie Li