emails failing to deliver to gmail addresses

[mnordstrom]

Lately when I send emails to recipients with gmail accounts they are returned as undeliverable. This only happens when I send from my legacy @adam.com.au account (my main email address). I get the message shown in the attached image file. Is there some setting I need to change?

[BasilDV]

Hi @mnordstrom

I've edited your post as it contains some Email address, which can be used to compromise your security.

Avoid posting any personal or account information on a public thread. If you are going to post an error message, kindly remove the key information.

The legacy mail account that you are using, is it under TPG? If yes, shoot me a PM with your TPG username or customer ID number.

BasilDV