Email will not send

[fostered]

iPhone and iPad will not send emails. I get this message”cannot send email user address invalid”.
I have changed passwords, restarted phone and iPad, reload email accounts, changed smtp address, all to no avail.
I can send email if I change email address in outgoing settings to another TPG email account.
Please help

[Riezl]

Hi @fostered, please send us a private message with the email address you're having issue with. To send a PM, please refer to this link: How do I private message (PM) in the community