title: VS Marketplace Add Member displayes Invalid Domain error
body: <p>I am trying to add a member to Visual Studio Marketplace. In my account I go to Manage Publishers &amp; Extensions -> Members and click om '+ Add'. Whatever e-mail I provide shows "Invalid Domain" error:</p>
  
  <p><a href="https://i.stack.imgur.com/thBKP.png" rel="noreferrer"><img src="https://i.stack.imgur.com/thBKP.png" alt="enter image description here"></a></p>
  
  <p>Is it a VS Marketplace bug or do I need to somehow link Azure directory (or any other users directory) first?</p>