title: ConversationId property vs ConversationIndex property in Exchange Web Services managed API
body: <p>EWS Managed API have two properties:<a href="http://msdn.microsoft.com/en-us/library/microsoft.exchange.webservices.data.item.conversationid%28v=exchg.80%29.aspx" rel="nofollow">ConversaionId</a> and <a href="http://msdn.microsoft.com/en-us/library/microsoft.exchange.webservices.data.emailmessage.conversationindex%28v=exchg.80%29.aspx" rel="nofollow">ConversationIndex</a></p>
  
  <p>What is the difference between them? I guess <code>ConversationId</code> is the the <code>ConversationIndex</code> of the first mail in the conversation which is essentially of 22 bytes, while <code>ConversationIndex</code> is the index of that particular reply in the conversation thread, essentially of 22 bytes + multiples of 5 bytes for each reply in the conversation. Is it like that?</p>
  
  <p>Also <code>ConversationId</code> is accessible only with Exchange Server 2010 onwards. So cant we access <code>ConversationId</code> in the Exchange Server 2007?</p>