Hi,
I would like to explain when a linked mailbox is created on resource forest A. The linked mailbox user is disabled and its msExchMasterAccountSID is set by using the linked user SID in user forest B.
If other users set Calendar permission to allow the linked user to access, the msExchMasterAccountSID is used because the linked mailbox user is disabled. Therefore, the linked user is able to access the calendar folder.
Nevertheless, if you create a new user on another user forest C and link to linked mailbox, a new msExchMasterAccountSID is set on the linked mailbox user ad object. The new user will not be able to access the previous calendar folder shared with old linked user in forest B.
Mike Shen
TechNet Subscriber Support in forum
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