Hi;
This a nice PowerShell exchange script that will output all of the permissions of all users in regards other mailboxes;
Can be very handy in some situations or either to have some sort of control
Get-Mailbox | Get-MailboxPermission | where {$_.user.tostring() -ne “NT AUTHORITY\SELF” -and $_.IsInherited -eq $false} | Select Identity,User,@{Name=’Access Rights’;Expression={[string]::join(‘, ‘, $_.AccessRights)}} | Export-Csv -NoTypeInformation c:\temp\mailboxpermissions.csv