I don't believe that true Folder/Calendar sharing is available between two Exchange Orgs.
I know we can set up federation between the two orgs and share free/busy information, but it is being requested that Full Calendar and Folder sharing is made available.
The only way I know to do this would be to set up a separate account within the same Outlook profile and provide a user the required access in the trusted forest/domain.
Is there anyone who has successfully done this without the use of a 3rd party solution.
Bobby Pendino