Outlook: Migrate Outlook Profiles to Office 365 (Wave 15)

Office 365, the current Exchange-2013-based incarnation ("Wave 15"), has (semi-)easy migration options from on-premises... except for the client-side, if your client-side is an existing Outlook 2007/10/13 based setup. Third-party tools, such as MigrationWiz, can fill the gap (possibly quite well), but if these are not an option, then read on.

Wipe Outlook Profiles & Start  Again

Now, the fastest way forward to migrate a fleet is to simply wipe all Outlook profiles & start again. Not that nice, but as long as your Autodiscover is working (and it is, isn't it? :) then all a migrated user has to do is click "Next" a lot when next opening Outlook.

Current advice that I found around the web is usually to just delete this reg key:
HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles
but this results in a horrible, confusing prompt when next opening Outlook ("select profile") which helps noone migrate. So don't do this. :)


My advice is to create a Group Policy, which uses GPO Preferences to delete several more reg keys/values and also a Folder. Set each entry in the Preferences to only Apply Once, and to Run in Users Security Context. All of the settings are User Settings, and not Machine.

Make your GPO delete the following reg keys:
HKCU\SOFTWARE\Microsoft\Office\14.0\Outlook\Setup\First-RunHKCU\SOFTWARE\Microsoft\Office\14.0\Outlook\Setup\FirstRun
HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles
And to also delete the folder:%LOCALAPPDATA%\Microsoft\Outlook

Replace/add more keys for the value above of 14.0 with as many versions  of Outlook as you wish to cater for [14.0 = Outlook 2010, 15.0 = 2013, etc].

Then:

• Set your GP's permission to only the users you wish to migrate (ie remove the Authenticated Users from the GPO; then for testing, make it only one test user; for Staged, simply add the each set of users as you stage-migrate them; for Cut-over, make it all users)
• Set the Computer Settings of this Policy to Disabled (all above setttings are User)
• Link the Policy to any/all OUs with User Accounts.

Can't I just use a PRF File with a Server Name?

Gone are the days (Wave 14 and prior) where you could simply apply a PRF file or other such niceities - Microsoft now hides the server name field and uses a per-user GUID (assigned when first migrating a user) as a Virtual Connection-Point. If your aim is to fully seamelessly migrate Outlook profiles (without  third-party tools) utilising manual configuration, then I leave this as an excercise to the reader (hint: you will need to create a per-user PRF file which sets up the VCP and uses the HTTP proxying connection attributes, and then apply this PRF to each respective user)