List all Users Who Have Access to Other Exchange Mailboxes:Change the items below that are in bold to fit your needs.
Powershell
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:\*location*\mailboxpermissionssource.csv
