If I login in a mailstore admin interface, I see the green cross in this server and the red cross in all the others servers (proxy/ldap server and the second mailstore server).
>> This issue will be resolve after little troubleshooting and configuration.
I don't want that administrator of domain1 see the accounts of domain2, and viceversa.
>> This can be achieve by creating two separate administrator account for domain1 and domain2,
Control there privileges by applying ACL and "Admin view" options.
Might be it helps. Delegated Administrator