Exchange 2007 Autodiscover Issue - Outlook wants password over and over again

If you get some connections issues with autodiscover that can be traced down to the msstd-checkbox, you might try this:

1. Set-OutlookAnywhere -ClientAuthenticationMethod:Basic -identity "2k7Server\RPC (Default Web Site)"
2. set-OabVirtualDirectory -identity "2k7Server\RPC (Default Web Site)" -RequireSSL:$true
3. set-OutlookProvider -id WEB -server "SERVER" -CertPrincipalName extern.fqdn
4. set-OutlookProvider -id EXPR -server "SERVER" -CertPrincipalName extern.fqdn
5. set-OutlookProvider -id EXPR -server $null

I saw a few people who did similar cmds, but this sequence did it for me. Other people related this issue to a certification problem.

Update: This isn't 100% correct, in addition you have to look at your certificate for the issued to name and put it at the CertPrincipalName.
Set-OutlookProvider EXPR -Server $null -CertPrincipalName msstd:extern.fqdn
Set-OutlookProvider WEB -Server $null -CertPrincipalName msstd:extern.fqdn

More discussion on this problem:
Only connect to proxy servers that have this principal name in their certificate
Outlook anywhere prompts for password