The trial version is limited in the number of syncable objects
GALsync description
Synchronize objects between multiple forests - Share information between Exchange organizations. NETsec's GALsync allows you to share Exchange mail-enabled objects of your Active Directory forest with other forests. Sharing objects helps users in one or both messaging organizations to access information about users and groups of the other Active Directory. Access to free/busy data between untrusted forests is also provided.
Software Library
