Its recently come to light that many of the new Microsoft products will not support configuration in a Single Label Active Directory (SLD), this configuration is where Active Directory domains and DNS name is simply named ‘Customer’ rather than ‘Customer.Com’ or ‘Customer.local’ - this is a fairly common practice for older Active directory implementations where the AD design may not have followed best practise.
The following products don’t work well/at all with an SLD
· Microsoft Exchange 2010, supports currently but does not like SLD’s http://support.microsoft.com/kb/2269838/en-us
Renaming the SLD to a proper namespace will not work, Migration solutions like the ones from Quest Software are the only valid way to migrate a non conformant SLD domain into one that will be supported with modern Microsoft server products http://support.microsoft.com/kb/300684/en-us, as many Microsoft server products will not function after a domain name change to fix the above problem.
At the current time there is no solution to this issue other than to use a Migration solution such as Quest Migration Manager for Active Directory.
With the release of Windows 2008 R2, Microsoft have prevented the creation of Single label Directories which will help in the future http://technet.microsoft.com/de-de/library/ee681710(WS.10).aspx.
