Store.IsConversationEnabled Property (Outlook)
Returns a Boolean value that is True if the store supports Conversation view. Read-only.
A store supports Conversation view if the store is a POP, IMAP, or PST store, or if it runs a version of Microsoft Exchange Server that is at least Microsoft Exchange Server 2010. A store also supports Conversation view if the store is running Microsoft Exchange Server 2007, the version of Outlook is at least Outlook, and Outlook is running in cached mode.
If a store supports conversations, calling the GetConversation method of an item in the store returns a Conversation object for the item. If the store does not support conversations, GetConversation returns Null (Nothing in Visual Basic) for items in the store.