After migrating from a Hosted Exchange 2010 environment to a dedicated Exchange 2010 environment I’ve seen sporadic issues. Very strange issue that I could not explain immediately. Autodiscover failed to work on one PC, but did work on another PC. With the same mailbox! To make it even more strange, Autodiscover did work for another mailbox on the first PC.

The Remote Connectivity Analyzer (RCA, http://www.testexchangeconnectivity.com) tested successfully, and the fact that Autodiscover worked fine on some PC’s proved that as well.

De “automatic e-mail configuration test” in Outlook failed after the first test and returned very little information. In this Exchange environment both OWA and Autodiscover are only accessible on port 443 (via TMG2010), so the warning is correct though:

After a couple of days (the mail component of Outlook was working) it became more clear, it’s in the “redirect check failed” warning. When you use a Hosted Exchange environment (or BPOS) yet get a redirect warning in Outlook about Autodiscover:

This information is somehow stored in the registry (in the Current_User part) and when you migrate your mailbox to another platform, these registry entries cause some issues. Therefore autodiscover doesn’t work on PC1 (with registry entries) and does work on PC2 (never used Hosted Exchange and therefore doesn’t have these registry settings).

These are the particular registry settings:

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\ Outlook\AutoDiscover
“ExcludeHttpRedirect”
“ExcludeHttpsAutodiscoverDomain”
“ExcludeHttpsRootDomain”
“ExcludeScpLookup”
“ExcludeSrvLookup”
“ExcludeSrvRecord”

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\ Outlook\AutoDiscover\RedirectServers
”autodiscover.exchange14.nl”

Remove the registry keys and/or entries and Outlook functions as expected.