Last Exchange Server Shutdown. Exchange Management Shell attempts to connect to old Server

1. Check the hybrid deployment configuration: Open Exchange Management Shell (EMS) and run the following command to check the hybrid deployment configuration:
powershell
Get-HybridConfiguration
If the hybrid deployment configuration is still present, you may need to clean up or disable the hybrid deployment.
2. Disable Hybrid Deployment: Open the Exchange Management Shell (EMS) and run the following command to disable Hybrid Deployment:
powershell
Remove-HybridConfiguration
Verify that hybrid deployment is disabled.
3. Check Exchange Server Roles: Open the Exchange Management Shell (EMS) and run the following command to check server roles:
powershell
Get-ExchangeServer | Select Name, ServerRole
Ensure that all Exchange server roles have been properly uninstalled or migrated.
4. Clean up Exchange-related components: Open Control Panel > Programs and Features and uninstall all Exchange-related components.
Manually delete the Exchange installation directory (usually C:\Program Files\Microsoft\Exchange Server).
5. Check DNS records: Ensure that DNS records (e.g. Autodiscover, MX records) have been correctly pointed to Office 365.
Delete the DNS records that point to the local Exchange Server.
6. Contact Microsoft Support: If none of the above methods work, it is recommended to contact Microsoft support team to provide detailed error messages and logs for further assistance.