We've got a proper DigiCert wildcard certificate which appears to be set up properly on Exchange 2007.
The Microsoft test site https://www.testexchangeconnectivity.com/ passes without any problems as does Test-OwaConnectivity & Test-OutlookWebServices internally.
Our problem is that internal Outlook users keep getting a message asking if they'd allow Autodiscover to configure Outlook and then a popup asking for credentials. If the user ticks a box to allow the autodiscover service to configure Outlook always, they still get the popup every time they open Outlook.
Any ideas?
What type of outlook version are you using? Outlook 2003 works different from Outlook 2007/2010.
Can you please specify the credentials settings for OwaVirtualDirectory and Microsoft-Server-ActiveSync directory.
I would also point out the need of correct InternalUrl and ExternalUrl.
By the way, microsoft-server-activesync is only for mobile devices, not for Outlook clients!