Normally when ever user leaves orginization his account will be disabled and Hidden from GAL. Some times chances that users are just disabled and not hidden from GAL. Where is the script which pulls out all the mailbox which are in Accountdisabled state and it hides the account from the GAL

Get-Mailbox -ResultSize unlimited |Where{($_.UserAccountControl -like “AccountDisabled*”)} | set-mailbox -HiddenFromAddressListsEnabled $true