E14 - How to List all Users Who Have Access to Other Exchange Mailboxes
http://exchangeserverpro.com/list-users-access-exchange-mailboxes/ [PS] C:\Windows\system32>get-mailbox -OrganizationalUnit System_Accounts | 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:\mailboxpermissions.csv