Outlook 2010 Free Busy \ Autodiscovery fails

While all other clients are working?
The Outlook 2010 hotfix package (outlook-x-none.msp) from February 22, 2011 will solve this problem.

Ask for the hotfix here.

Open multiple user mailboxes in OWA 2010 simultaneously

Many organizations work with owa 2003 as their client’s mail client. In owa 2003, if you wanted, you could open as much windows as you want, each with a different mailbox. In owa 2010, If you tried that, you probably know it’s impossible. EWS 2010 will allow for only one user at a time per session. No matter if you try to use tabs, new windows – you get this annoying error:
“You may have already opened your mailbox on a different browser tab. If you feel you’ve received this message in error, try refreshing your browser.”

The first workaround was to work with different browsers, but then you get all messesd-up with IE, Mozilla, Chrome (?!) and the clients get frustrated.
So we came up with this:

If your end users can handle it (and for your IT staff), ask them to open a new session in IE:

Since most of the customers use desktop shortcuts or predefined urls in the favorites tab, the smarter solution would be to create these shortcuts with the following argument:

"C:\Program Files\Internet Explorer\iexplore.exe" -noframemerging https://&lt;yourCASname>/owa/<user's email address>

This will allow you to open multiple windows with multiple users mailboxes:

Unfortunatelly, it is impossible to achieve this using tabbed browsing.