Discovery services did not return a valid Exchange Web Service URL: The Exchange Web Service (EWS) URL associated with the mailbox could not be located. This may happen for the following reasons:
- The account does not exist or has no provisioned mailbox.
- The mailbox was created recently and it takes time for replication to occur.
- The mailbox is associated with a kiosk (desk-less) Office 365 plan, which limits EWS access.
- Office 365 discovery services returned an empty response.
Verify that you can log in to the mailbox at http://mail.office365.com. If using administrative credentials:
- Log in to the administrator's mailbox.
- Click the user name at the top right corner.
- Click on Open other mailbox.
- Enter the email address associated with the mailbox.
- Click Open.
If the mailbox is associated with a kiosk Office 365 plan, and you are NOT using administrative credentials, consider specifying administrative credentials on your connector. Kiosk mailboxes have limited access to Exchange Web Services. Using administrative credentials can work around this limitation. Make sure the admin account has impersonation rights configured.
If the mailbox is NOT associated with a kiosk Office 365 plan, check that Office 365 discovery services are responding properly by testing access on Microsoft's connectivity test website.
Finally, consider waiting for replication to occur if the mailbox was provisioned recently.