Problem with Outlook (client) 2010/2013 profiles on Exchange 2013

Question

We have recently started migrating to Exchange 2013 and have come across a problem with some of our accounts. This problem exists in both migrated mailboxes and natively created 2013 mailboxes.
basically we have a lot of "shared" accounts.  We create a user object in AD, give it a mailbox, then give a security group "Full Access"  (and often "send-as") permissions on the account.  We then Disable the
account in AD (to prevent directly using the password) and then add/remove group members to manage access. everyone uses their own credentials to get to the account.
For the most part this works fine. Users can access OWA and get to these shared mailboxes, they can also 'add' the mailbox to their Outlook client by going into Account Settings->Properties of the Exchange user->More Settings... ->Advanced Tab->"Open
these additional mailboxes:" and adding the mailbox.
However what has happened is that some users were setting up a separate profile instead of adding a mailbox. (Pretty much these
instructions: )
When this is done an error occurs. :
Cannot open your default e-mail folders. You must connect to Microsoft Exchange with the current profile before you can synchronize your folders with your Outlook data file (.ost).
Connecting with a profile set up as yourself first does not clear the error, whenever the shared mailbox folder is selected you get this.  The exception is if you go into the account properties and turn off Cached mode. the error then becomes:
Cannot open your default e-mail folders. the file c:\users\[user]\appdata\local\microsoft\outlook\[datafile].ost is not an Outlook datafile (.ost).
Which is weird since migrated accounts had working OST files which were functional prior to migration and outlook creates the new OST for new accounts.  This message appears to be a red herring and the problem is still sync access but it throws this
error instead.
In the end is creating a new profile for a mailbox you have Full Access to no longer supported in 2013 or is there something we can do to fix this problem?

Answer 1

Hi AD-Tester,
According to your description and I do an test, however I cannot reproduce the problem.
I want to confirm some points, please help to collect answers for following questions:
1. Check all account or some special user face this problem.
2. Try this command to check Atodiscover, Exchange Web services, Availability service, Offline Address Book services works well:
Get-ClientAccessServer | Test-OutlookWebServices -Identity 'e-mail address'
If it works on OWA, problem may point to outlook client. Please try to re-create a outlook profile for testing.
Note: please make sure set properly setting for Outlook anywhere.
Additional, we can recreate an account and enable-mailbox, then disable in AD and try to login outlook account again.
Best Regards,
Allen Wang