I live  in canada , so I dont have problem to download  this software, But we have already installed MS active  Directory and we are using that.

1- why do I need to install  this software? what are benefits of switching to penLDAP ?

2- I could access to AD and I could list users in each department . but I dont know how to fetch their emails? I am getting errors when I use any string  filter .It means I am just able to list not search(doesnt make sense to me either)

3- How can I know which kind of microsoft active directory  I am using?