Working on Exchange/Outlook 2010 I understand conversations should be linked by "conversation index" despite of the "subject" line to be changed during the "conversation"... is that correct?

In my case "conversations" appear to be grouped by "subject" which means, any change to the "subject" during a reply is starting a new conversation.

Environment:
Exchange version: 14.3.235.4001 which I understand is Exchange 2010
Outlook version: 2010

Is this a known issue?
Am I doing something wrong?
Is it there a step-by-step guide to get this working? meaning, conversations grouped by "conversation index" rather than "subject"?

Any and all help would be much appreciated.

PB

• Edited by PaulB_new Thursday, July 23, 2015 6:08 AM Typo

Hi Paul,

I'm afraid what you described is by design in Outlook 2010. The conversation view mode is a new feature in Outlook 2010 and it controlled by the parameter Conversation ID. We may check it through MFCAPI tool (http://mfcmapi.codeplex.com/) or get it via script (http://msdn.microsoft.com/en-us/library/microsoft.office.interop.outlook._mailitem.conversationid.aspx#Y97). See a screenshot from MFCMAPI:

When we modify the subject and reply/forward the mail, Conversation ID will be changed. Moreover, this parameter is read-only permission and we cannot modify it for some security reason. 

Hope this helps.

Regards,

Steve Fan
TechNet Community Support