ConversationID for MailItem in different versions of outlook

Question

I am working on outlook plugin, which logs mails to our system. We want one entry per mail thread/chain. We are developing 2 versions(for outlook 2003 and 2010) of plugins.

For outlook 2010, I am using property ConversationID of MailItem to identify mail thread. Is it safe to use this property ? Is conversationId same for mailthread same no matter whats version of exchange server ?

For outlook 2003, I do not find this property. I see ConversationIndex property. Can this be used in any way ?

Some of our users will be using 2003 and some will use 2010, id that we use for mail thread should be same across different versions of outlook.

Answer 1

PR_CONVERSATION_INDEX MAPI property was used as far back as Outlook 97 if I remember correctly.

Outlook 2003 Object Model does not expose that property, but it is still there on the MAPI level. Since PropertyAccessor was not exposed until Outlook 2007, your options are CDO 1.21 or Redemption.

Answer 2

Here is what I am thinking of doing to identify conversations logged to our system from outlook.

Outlook 2003 -

Use (first 44 characters of ConversationIndex)+user id. I had to append user id as conversation index for same mail chain can be different for different user machines.

Outlook 2010 -

Using conversation id. My assumption is this conversation ID is generated at server and would be same a mail thread on all user machines.

Please correct me if I am missing anything.