
Alessandro.panzetta |
At first impression I would say that is related to permissions, OWA uses AD information to reach the mailbox, it tries but doesn’t succeed reporting the error; give a try creating another mailbox from AD and see if the error occours again.
Let me know.

Technochic |
Unfortunately if you create a mailbox in AD, you cannot log into OWA with it. You will get an error “A problem occurred while trying to use your mailbox. Please contact technical support for your organization.” Therefore this is not a good test.
Here is a good article on creating mailboxes in Exchange Management Console for Exchange 2007
<a href="http://articles.techrepublic.com.com/5100-10878_11-6169714.html" rel="nofollow">http://articles.techrepublic.com.com/5100-10878_11-6169714.html</a>
also this one
<a href="http://www.computerperformance.co.uk/exchange2007/exchange2007_create_mailbox.htm" rel="nofollow">http://www.computerperformance.co.uk/exchange2007/exchange2007_create_mailbox.htm</a>
These may help you find where your error was in creating the mailbox.