@Stanton, Daniel, Thanks for posting in Q&A. For the error message, it seems the device is still managed by the previous company.
Please try the following suggestions to see if we can add the new email:
- Please see if the company porta is accessible. If yes, try to remove the device via company portal. https://learn.microsoft.com/en-us/mem/intune/user-help/unenroll-your-device-from-intune-ios
- Ensure the previous email account and profile is removed from outlook and the device. App protection policy with the previous email account may affect to add new email account.
Please try the above suggestion and if there's any update, feel free to let us know.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.