Outlook 2010 prompting for credentials after moving to hosted exchange/office 365

We’ve been migrating to hosted exchange on Office 365 for some weeks now. Some of our Outlook 2010 clients have a problem once they’d been moved.

After many hours of trying different things and searching I found a Microsoft Patch that resolved the problem.

The KB Number is – KB2791026 downloads can be found here KB2791026

Also check out my previous post about delegated mailboxes, you may find the two issues are linked