To view the permissions of a specific folder within a mailbox, the command Get-MailboxFolderPermission can be used to accomplish this task. The examples below illustrate how to use the Get-MailboxFolderPermission command.

Example 1:

In this example, the Get-MailboxFolderPermission command will be used to export the users and their associated access rights for the Calendar folder of each mailbox within the organization. You can swap out Calendar from the syntax below with any folder within the mailbox. This includes non-default folders.

ForEach ($mbx in Get-Mailbox) {Get-MailboxFolderPermission ($mbx.Name + “:Calendar”) | Select Identity,User,AccessRights | ft -Wrap -AutoSize}

The Identity field provides the name of the mailbox associated with the calendar folder

The User field is the user that has rights to a the specified folder

The AccessRights field is the access rights the user has to the specified Mailbox folder

Example 2:

In this example we will only return the mailbox permissions for mailboxes that are in the Organizational Unit (OU) CB5Lab.com/Solutions/Users/.

ForEach ($mbx in Get-Mailbox -OrganizationalUnit CB5Lab.com/Solutions/Users) {Get-MailboxFolder Permission ($mbx.Name + “:Inbox”) | Select Identity,User,AccessRights | ft -Wrap -AutoSize}

Example 3:

The final example uses the Where filter to only return mailboxes that user Chris has access rights to. The command below pulls all the mailboxes in the OU CB5Lab.com/Solutions/Users and filters the list of mailboxes returned to the command window based on if the user Chris as access rights to the Inbox folder.

ForEach ($mbx in Get-Mailbox -OrganizationalUnit CB5Lab.com/Solutions/Users) {Get-MailboxFolderPermission ($mbx.Name + “:Inbox”) | Where {$_.User -like “Chris Crandall”} | Select Identity,User,AccessRights |  ft -Wrap -AutoSize}

 

Reference

http://social.technet.microsoft.com/Forums/exchange/en-US/c3ffb685-32b0-4799-a74d-e355eb8456ae/a-list-of-all-calendars-a-user-has-access-to?forum=exchangesvradmin