Hi Guys,
I have been troubleshooting the infamous “authentication/login” issue on Outlook 2010 Windows XP clients for the last three days. Today I think I finally succeeded in getting it to work, although I need to perform an odd step in order for this to work, which I need to avoid/correct and figure out what is going on, so my users do not need to perform this step during migration or initial profile logon.
I am literally stumped on this one. This has to be the most puzzling and odd issue I have come across in my I.T. career in the last 15 years. *minor rant* Damn you Microsoft! *end rant* Disclaimer: This has to be the first time I have ever said that. Wow…
Anyhow to the point, explanation and question.
On a clean XP profile (admin user or not), autodiscover successfully retrieves the clients connection details and proceeds to query me for a username and password, no combination will work at this stage (Username, UPN, Email or Domain/Username).
*here is where things begin to get interesting*
I launch Internet Explorer proceeding with the URL of OWA - the browser loads OWA, I then proceed to close the browser. No login is required at this point, just a logon screen.
I go back to Outlook launch it, autodiscover begins to do its discovery and voila, success. No login screen prompts and Outlook 2010 successfully connects to Exchange 2013.
My initial suspicion was that the purchased certificate is not being added or trusted rather by the users profile at this stage, hence loading Internet Explorer loads the certificate either into memory or some sub-system process which then allows me to authenticate via NTLM. I am not sure if this is the root cause or not, but it seems to be the only logical explanation at this stage.
I am fortunate (so to speak), it was just those out of luck attempts. “Hey, let’s try to see if OWA works – Great! OK Let’s go back to Outlook – hey what do you know, it worked”.
I have re-tested this practice over and over for the last 5 hours trying to capture system changes, nothing appears obvious in the system track changes (registry or file). I’ve made sure the profile was always fresh and can confirm that all users on Windows XP connecting to exchange 2013 have this issue. The same users on Windows 7 do not have this issue at all with Outlook 2010. Just Windows XP with Outlook 2010 connecting to Exchange 2013. Again, weirdest thing I have come across. Hopefully somebody has further knowledge about the internal working on this process that allows my XP clients to connect. I am literally baffled, perhaps been working on this issue far too long and it has fried my brain.–
P.S. The Windows clients are all fully up to date with Windows and Office updates.
Let’s hope somebody can help me make sense of this and figure out what the hell is going on.
Cheers…