I found that 30% of my emails were not going through. I worked with support and this is what i found.
Godaddy is phasing out this product and will be moving to office 365.
There are no bounce back notifications for unsent mail
Your IP is potentially blocked without knowing so you need to escalate this with support.
It would be great if Godaddy warns users that they're removing the email service from their portfolio and that you may experience issues. It would also be great if they would provide bounce back notifications or notifications about your IP being blocked. If you're using Godaddy email, switch to another service immediately.