title: Outlook 2016 doesn't call SynchronizeInBackground
body: <p>In case when <code>CMsgStore::QueryInterface</code> method queries for the <code>IID_IMAPISync</code> it returns my own implementation (CSync) of the <a href="https://docs.microsoft.com/en-us/office/client-developer/outlook/mapi/imapisynciunknown" rel="nofollow noreferrer"><code>IMAPISync</code> interface</a>. Later the CSync object got two method calls of <code>CSync::AddRef</code> and then two method calls of <code>CSync::Release</code>.</p>
  
  <p>Can anybody help me to learn why the <code>CSync::SynchronizeInBackground</code> method isn't called?</p>