HI Powershell Guruz; I received some help for the script in the thread below.
No I need to somewhat reverse it, need to get all user who are not a member of the but, but have value in -CustomAttribute1 - and after that clear CustomAttribute for those users --- any ideas?
$users = Get-ADGroupMember Test_MBX_Permission | Select-Object -ExpandProperty name
foreach ($user in $users)
$userinfo = Get-Mailbox -Identity $user -ErrorAction SilentlyContinue | select
if NOT A MEMBER OF THE GROUP
#If customattribute1 have value - SET VALUE TO Null