As we used to use some awful hosted Exchange 2003 platform we decided the first thing to be moved was Exchange…. So as all the users were on a separate domain we created a lavish Exchange 2010 platform and used linked mailboxes for everyone and migrated the mail!! Think I posted on how we did this earlier…basically created the linked mailboxes via PowerShell and a CSV file then ExMerge the mail out of Exchange 2003 and used a PowerShell import command to pull the mail in (although you could use new PST Capture tool now to import which provides a pretty GUI).
So here we are, linked mailboxes as far as the eye can see, full of crappy mail!
Next we setup Auto Discover on all our domains to point to exchange and bobs your uncle.
So, everyone is working away…and suddenly people start complaining they keep getting prompted for their username and password credentials in Outlook 2010 running Windows 7!
Ok I think, you’d expect it once or twice due to going cross domain but not 20 or 30 times!!
The Fix, after trying everything we discovered it was down to AutoDiscover and it not being routed internally!
Added it (it being AutoDiscover.Domain.com) to the proxy exclusion list in IE and wham! No more prompts!