Rajeev Pentyala – Technical Blog on Power Platform, Azure and AI

Other while importing a solution from market place, I had to create a Office 365 Outlook connection to complete the setup.

However got following “REST API is not yet supported for this mailbox” error while creating the connection.

Reason and fix:

Error could be because of 2 reasons

• Missing valid license
  • Troubleshoot this by logging to https://outlook.office.com/. If you could connect, then the issue might not be with license.
  • But if you get an error similar to below while logging to https://outlook.office.com/, its because of missing a valid license.
  • Ask your Admin to grant the User with either Office 365 or Azure Active Directory Premium license.

UTC Date: 2022-10-18T09:30:08.758Z
Client Id: xxxxxxxxxxxxxxxxxxxxx
Session Id: xxxxxxxxxxxxxxxxxxxx
Client Version: 20221006031.10
BootResult: configuration
err: Microsoft.Exchange.Clients.Owa2.Server.Core.OwaUserHasNoMailboxAndNoLicenseAssignedException
esrc: StartupData
et: ServerError
estack: Error: 500
    at f (https://outlook.office.com/mail/:341:261409)    at https://outlook.office.com/mail/:341:269776
st: 500
ehk: X-OWA-Error
efe: xxxxxxxx, xxxxxxx
ebe: xxxxxxxxxxxxxx
emsg: UserHasNoMailboxAndNoLicenseAssignedError

• Missing ‘Mail Box’ configuration
  • Make sure a Mailbox is configured for the user

🙂