When trying to send mail from the TPG Post office I recieve the following message.
Failure sending message: Email address not valid. Please use an email address which looks like email@example.com
However, as can be seen in the attachment, I am using correct eail address protocols.
Welcome to the Community!
Could you please send me a PM with the Email address that you've experienced the issue? Is it a certain address or all of the email addresses?
Have you tried to open the TPG Post Office using a different browser and try sending the email?
What are the troubleshooting that you've done so far?