As I have got no answer, I have contacted the Microsoft support:
A short sum up of my issue:
I use OCS 2007 Standard with Exchange 2007. I manage a lot of sip domain, so I would like to manage easily the visibility between these domains. So I used Access Levels Management.
I changed the Access Level of the group People in my company to Blocked, and I have changed the group People of myDomain.fr to the Company level.
So now all the other use from the other domain see me as offline and cannot contact me.
However when I try to contact my voice mail I have an error message that the Voice mail is not available.
What the support responds me:
I use the ACE in the wrong way. They propose me to use a management by OU or by SIP domain.
1) OU management :
· EthicalWallsSample : http://www.microsoft.com/downloads/details.aspx?familyid=070dbcab-472a-4ec1-aeac-9273eccd70c9&displaylang=en
· ABS Configuration Tool from Resource Kit of Microsoft Office Communicator Server: Partition ABS data by Organizational Unit and create individual ABS files per OU. User will be able to search only on the same OU, but if they know the SIP address of the user, they will be able to contact them.
2) SIP domain management: Creation of a pool by SIP domain, but we must use an OCS Server by pool.
3) dbimpexp.exe :
Export of the property of a user with DBExport -> Creation of an XML file
Creation of other similar XML file for the other user
Import of the data with DBImpexp
It requires to stop the OCS service during the export and the import.