title: How does auto-login Outlook successfully when in AD environment?
body: <p>When I logon to my company's computer with the AD username/password, I find that my Outlook will launch successfully. That means the AD authentication has passed.</p>
  
  <p>In my opinion, outlook retrieves the AD user information, then sends it to an LDAP server to verify.</p>
  
  <p>But I don't know how it retrieves the information, or by some other methods?</p>