We're in the middle of a messy migration at the moment. We have purchased another company and have brought them onto our premises. We just basically picked up their whole network and brought it on premises, but they are still in their own little bubble so to speak.
So we have 2 separate networks, with 2 separate Windows 2008 Active Directories, with 2 separate Exchange servers etc.
We have slowly been migrating people across into our environment. Domain A is our environment. Domain B is the company we bought.
We have migrated some computer accounts and domain accounts across to Domain A, whilst leaving their Exchange mailbox in Domain B.
We have also migrated some mailboxes across to Domain A whilst leaving their computer and domain and computer accounts in Domain B.
We weren't going to do a full Federated Trust thing with Cross Forest Migration. We are just exporting their PST from their Exchange 2010 server on Domain B, and importing it into their Domain A mailbox account.
So, the user is logged into a computer that is a member of Domain B, with an AD account that is a member of Domain B. When we configure their Outlook for the Domain A Exchange Server, it prompts for Domain A credentials, and they are good to go. (We have configured them with accounts in both domains).
I've just noticed though that Out of Office is not working, and neither is the Free Busy information.
For people that are logging into their computer using Domain A AD accounts and Domain A Exchange mailboxes, everything works properly. But for people that are logged in as Domain B accounts, this doesn't work.
I've done the Autodiscovery test within Outlook, and I notice that the first thing it does is look for autodiscovery information for Domain B, but then moves onto Domain A and it is successful.
I know this is a messy scenario, but it is necessary for a short period of time until we can sort some things out.
I'm just wondering if it's some sort of permissions thing in IIS for Exchange Web Services, or it's just the fact that this won't work because their AD account is still in Domain B.
I've also tried the registry hack to prefer a local XML file, and used the Autodiscover details for Domain A, but that doesn't work either.
Anyone got any ideas?