title: Recursive folders list in Office 365 unified API
body: <p>I am trying to get list of mail folders using Microsoft Graph unified API. By default it returns 1st level of folders only(no child folder). so I used $expand=childFolders to get child folders too. again it returned 1st &amp; 2nd level of folders but not 3rd and 4th level. <br/>
  I tried OData $levels to get folders upto 5th level but it is not returning. <br/>
  I don't know $levels is supported by unified API or not because its not found anywhere in unified API's website.
  <br/><br/>
  has anyone idea how I can get all folders in single request?
  <br/><br/>
  I used this url :  </p>
  
  <blockquote>
    <p><a href="https://graph.microsoft.com/v1.0/me/mailFolders" rel="nofollow">https://graph.microsoft.com/v1.0/me/mailFolders</a>?$top=50&amp;$expand=childFolders($levels=5)</p>
  </blockquote>