"Sender not verified" displayed when sending using Email Templates

"Sender not verified" displayed when sending using Email Templates

Dear Zoho Team,

We are experiencing trouble with ZOHO CRM when sending out emails with Email Templates that we have created.

We added a new email address, verified it, then set it to Primary Email address. Following which we sent out a mass email using one of our Email Templates.

The email was in good order. Except the subject title which had " [Sender not verified]".

Thank you!
Gareth