PowerShell: add and remove send-as permissions
Adds the sendas permission to a user object using ExtendedRights
add-ADPermission -identity "CN=Arnout van der Vorst,OU=Accounts,DC=tools4ever,DC=local" -user "CN=Ab Vos,OU=Accounts,DC=tools4ever,DC=local" -AccessRights ExtendedRight -ExtendedRights Send-As
Removes the sendas permission from a user object using ExtendedRights and automatic confirmation
remove-ADPermission -identity "CN=Arnout van der Vorst,OU=Accounts,DC=tools4ever,DC=local" -user "CN=Ab Vos,OU=Accounts,DC=tools4ever,DC=local" -AccessRights ExtendedRight -ExtendedRights Send-As -Confirm:$false