Auto-discover works fine, Establishing network connection - green check, Searching for the user - green check, then on login it fails with "The connection to Microsoft Exchange is unavailable.  Outlook must be online or connected to complete this action".   This issue just started happening for a single user, and follows the user to any PC we try to setup Outlook on, so it definitely seems to be an issue with her specific mailbox or account.  OWA does work, and she's able to sign in and check her mail here.

Is there any kind of maintenance that can be ran to fix this?  Any idea's why should would have been working fine for months, and then this issue come up out of the blue?

RCA shows:

The address book Bind operation failed with status -2147467259. NSPI Status: 2147500037

• Edited by JoeFri 16 hours 11 minutes ago

Run Get-CasMailbox <user> | fl 

and look to see if MAPIBlockOutlookRpcHttp is set to true.  

If it is, then run Set-CASMailbox <user> -MAPIBlockOutlookRPCHttp $false

Oky well, recycling the AppPools for both Autodiscover and RPCProxy fixed the issue... I was able to setup Outlook without issue after that...  Any idea's on the cause here?

• Marked as answer by JoeFri 16 hours 2 minutes ago

Thanks Hinte, Checked this after the AppPool recycle and after she worked, they are both set to False.   Would recycling an AppPool have been able to change this setting?  Or could there have been some kind of Throttling that triggered a "true" here?

• Edited by JoeFri 15 hours 55 minutes ago

Thanks Hinte, Checked this after the AppPool recycle and after she worked, they are both set to False.   Would recycling an AppPool have been able to change this setting?  Or could there have been some kind of Throttling that triggered a "true" here?

That won't affect those values.  It is enabled by default, but I have seen users disable it for various reasons on older versions of Exchange (2010/2007).