Disabling AD Autodiscover while migrating to Office 365

Question

I'm in the middle of migrating from Exchange 2007 to Office 365.  I can autodiscover to the Office 365 service successfully in every instance except when I'm on a PC joined to the AD domain and the domain is accessible.  I have added a registry
key on my test PC that keeps it from using the AD SCP to autodiscover but it still gets my Exchange server mailbox instead of the Office 365 mailbox even without using SCP.
If I remove the PC from the domain, it works both locally and remotely so I know all my other settings are okay, it's only giving me this issue when it's a domain member and is running local to the AD domain.  Tried a laptop, joined it to the domain,
took it home and let it autoconfigure, worked great.  Same laptop, when local to the domain, tries to autoconfigure using the local Exchange server settings.
I'd like to give my users back their Outlook (rather than OWA) after I migrate them.  How do I prevent my locally deployed, AD-joined computers from getting autodiscover info from my local Exchange CAS server while I complete my migration to Office
365?

Answer 1

Hi,
I ran into the same problem. I came up with a work around but I’m not sure this is the correct approach.
First, with Outlook 2010 already installed I had to run the Set up and configure your Office desktop apps from Office 365. I’m not sure of all the configuration changes this makes but I know after you install it that it will allow
you to change the username field when trying to authenticate to Office 365 (will get back to that in a minute)
Second, from my domain joined computer where outlook was connected to my on premise exchange 2007 server mailbox, I setup a new outlook account, either from the control panel mail icon, or from within outlook (both worked) Note; doing from within your already
existing configured outlook allowed me to migrate my email from on-premise to office 365.
From Control Panel/Mail , I created profile name “Office 365”
In the next window it then auto discovered my on premise exchange mailbox email address
[email protected] (which in my case is the same as the office 365 email address
[email protected] )
I replaced the email address with the secondary domain email address that Microsoft office 365 created
[email protected]. I did not put in password at this point and clicked next. It then searched for mailbox, a windows security mail application windows will pop up.
This is where I then replace username
[email protected] with
[email protected] and put in my office 365 account password.
As mentioned above when I said I would get back to that in a minute, if you don’t run the
Set up and configure your Office desktop apps from Office 365. You will not have the option to replace the username from the windows security mail application windows.
It finishes configuration and you’re now connected.
Worth mentioning though that I’m still having some funky mail delivery issues with on-premise users with my imported “contacts” in outlook. The contacts work from office 365 web apps, but not from outlook. If I type the address everything
is fine, but using contacts or replying to on-premise users is giving me some grief. It’s a contact issue but I’m still unable to resolve it.