As soon as Outlook starts up inside an SBS Lan it will look for autodiscover settings on your server and connect to the Exchange Server running on your SBS 2011 and that is what you do not want. On the SBS we run Remove-AutodiscoverVirtualDirectory to remove the virtual directory that causes the unwanted behavior but first we need to figure out what the identity is of that directory. We do that by running Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, ExternalUrl, Identity from within Exchange Management shell. Start an elevated Exchange Management shell from the start menu. Run Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, ExternalUrl, Identity and copy the identity to a text file. In our case that is “ADATUMSERVER\Autodiscover (Default Web Site)” Before we continue I want to make a backup of the IIS configuration so we can return to the situation where the virtual directory is still in place. Open an elevated command prompt from the Start Menu. Run %windir%\system32\inetsrv\appcmd.exe add backup 'Before Removing Autodiscover' . That will create a backup that can easily be restored. If you ever need to restore your backup read this http://blogs.iis.net/bills/how-to-backup-restore-iis7-configuration . Now that we have made our backup we can delete the virtual directory by running Remove-AutodiscoverVirtualDirectory –Identity 'ADATUMSERVER\Autodiscover (Default Web Site)' Just a quick check if it is really gone: Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, ExternalUrl, Identity and see it is gone. If you can I would reboot the SBS just to be sure.