title: Azure AD B2C - "emails" claim in custom policy
body: <p>I'm looking for a way to add an <code>emails</code> claim (collection of emails) to a custom policy for Azure AD B2C.  This application claim is available from the Azure Portal directly but I cannot find a way to implement this in a custom policy which I need to create.</p>
  
  <p>What I want to achieve is to have Azure AD B2C authentication for my WebApp users and Azure AD authentication as custom Authentication Provider for employees so It means I will need to add <code>emails</code> claim twice - for Local accounts and for Azure AD. </p>
  
  <p>I followed <a href="https://docs.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-setup-aad-custom" rel="noreferrer">this guide to make custom policy</a> so I've added a new <code>ClaimsProvider</code> to TrustFrameworkExtensions.xml file.</p>
  
  <p>When I download Sign Up &amp; Sign In policy created in Azure Portal then I can see the following Output Claim:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;OutputClaim ClaimTypeReferenceId="emails" /&gt;
  </code></pre>
  
  <p>I tried to put that line to my custom policy but it does not return <code>emails</code> claim.</p>
  
  <p>Any ideas?</p>