Are you getting this error when running Get-MailboxFolderPermission? PS E:\> Get-MailboxFolderPermission deptcalendar@company.com:\calendar The security principal specified is already on the permission set.     + CategoryInfo          : NotSpecified: (:) [Get-MailboxFolderPermission], CorruptDataException     + FullyQualifiedErrorId : [Server=ZN1UR12MB0288,RequestId=b4f155be-a238-4a98-8b3f-f3d9258e22d2,TimeStamp=6/19/2018 10:10:41 PM] [FailureCategory=Cmdlet-CorruptDataException] F8D77EE2,Microsoft.Exchange.Management.StoreTasks.GetMailboxFolderPermission     + PSComputerName        : outlook.office365.com The error message seems cryptic, right? But it is not. It … Continue reading Get-MailboxFolderPermission – The security principal specified is already on the permission set →

As Exchange Administrator, if you want to find out any user's mailbox size information by folder and number of items in each folder, you can to the right place. Here is the PowerShell Command to list the folders, number of items in the folder and size of the folders. Replace the username@domain.com with user's primarySMTPAddress. … Continue reading Exchange: list mailbox folders size and items count →