Summary - Local users with desktops are set to connect to Exchange via Outlook. However, when checking the Exchange Proxy settings, you'll find that they have proxy settings setup. This is not desired when using a local desktop on the same network as an exchange server as it can connect via TCP/IP directly without any proxy configurations. The Proxy configurations will sometimes prevent users from being able to access or even send emails.
Exchange Management Console (2010)
- Perform Get-OutlookProvider and note down the settings and record them incase the server needs to be reverted back
- Run these 2 commands in EMC
- Set-OutlookProvider -Identity EXPR -CertPrincipalName $null
- Set-OutlookProvider -Identity EXPR -Server $null
- Run Get-OutlookProvider once more to confirm the new settings (which should all be blank)