title: Check if List of Users are valid against adfs in C#
body: <p>I have a requirement to check if the users in my application are active users in active directory.
  I need to send a notification when one of the user alias becomes invalid.</p>
  
  <p>In most of the examples I see validating only one user at a time against ADFS using LDAP which is going to take a very long time large number of users.</p>
  
  <p>Is there any way by which I can validate by sending a list of users and validate, so that it will be faster?</p>
  
  <p>Thanks.</p>