Hi @grahamjc ,
Thanks for raising this to us, please test if you can send an email using your post office (https://www.tpg.com.au/home/postoffice) if so, please shoot me a private message with the following details below.
Affected E-mail address:
Address on file:
I have an error message saying the sender address is not verified from my iPhone mail app using my TPG account thus I am unable to send emails from my phone. I have changed my password and I can still send emails from the TPG post office. I can also receive emails. Can you please look into this.