During a migration to Office 365, a user’s computer connects to the local Exchange Server when configuring an Outlook profile instead of connecting to the Office 365 server.
The AutoDiscover Service is running in the local Exchange environment, causing the clients to connect locally.
To repair this issue, perform the following:
- Log into your local Exchange Server as an Administrator
- Open the Exchange Management Shell as administrator
- Enter the command Get-ClientAccessServer and press enter. Make note of the returned value
- Enter the command Set-ClientAccessServer -Identity “VALUE” -AutoDiscoverServiceInternalUri $NULL (Replace VALUE with the CAS server noted in step 3)
- Open the Services Console and locate the Microsoft Exchange Transport Service and restart the service
- Open the DNS Management Console and be sure that there are no CName Records for Autodiscover.DomainName.com , or point the record to AutoDiscover.Outlook.com