You may get a bounce back email when sending Email-to-SMS:
We've successfully delivered your SMS messages, however, there were some errors with these recipients:
•xxxx - Missing Required Fields
This is normally caused by an empty email subject and body.
If you think the subject and body is there but you're still getting this error, please report it to our support team who will investigate for you.
Our award-winning customer care team is here for you.Contact Support