Just a quick warning, it looks like the latest Office patch has messed up the search facility in Outlook. We started seeing problems last week, search stopped working and people with multiple email accounts linked to their main account (Exchange accounts) suddenly couldn’t send emails from these sub-accounts any more, even though they still had the “send as” permission on the Exchange server.
It looks like the cache settings are a bit messed up (my Outlook was set to use no caching, the search suddenly stopped working and looking at the settings, Outlook thought it was caching 1 months worth of emails). Resetting the cache settings (turning caching back off or turning it on and off or vice versa) seems to clear the problem, at least temporarily.
For some of our users, we had to delete the “send as” address in the “from” field in Outlook and re-add it. Normally, you can just type in the address and it works, but in our cases, we actually had to click on the “from” button and select the address directly out of the Exchange address book, even though it was the same address as had been manually entered!
This article pretty much covers it.