One of the drawbacks of performing a cutover migration from an On Premise Exchange environment to Office 365 is that Outlook profiles must be recreated to connect to the Office 365 servers. If done manually on every single workstation in your company, this could be a very time consuming process as you would have to create a new profile, set it as the default and configure it for the user.
One way of automating some of this process is to use Group Policy to run a script to create a new blank Outlook profile and set it as the default profile. The user will then be presented with the first time profile setup screen when opening Outlook and should be able to use Auto discover to automatically find their new Office 365 profile settings:
To create the batch file required to do this, copy and paste the following text into a file and save it as a .bat file:
For Office 2010:
reg add "HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\O365"
reg add "HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles" /v DefaultProfile /t REG_SZ /d "O365" /F
reg add "HKCU\Software\Microsoft\Exchange\Client\Options" /v PickLogonProfile /t REG_DWORD /d "0" /f
For Office 2013:
reg add HKCU\Software\Microsoft\Office\15.0\Outlook\Profiles\O365
reg add "HKCU\Software\Microsoft\Office\15.0\Outlook" /v DefaultProfile /t REG_SZ /d "O365" /F
The script will create a new profile called O365 and set it as the default profile. Create a new Group Policy object to run the .bat file in Group Policy Preferences. You can safely leave the GPO in place for a few days to allow for people who may not be in the office for your go live day as it will not overwrite or remove existing profiles.
When this process in used in conjunction with the Group Policy for controlling Auto discover (http://doubledit.co.uk/2014/10/21/controlling-autodiscovery-using-group-policy/) you can have a 80% automated cutover migration which should be smooth sailing for yourself and your users!