VSTO Outlook add-in: Office 365 groups Outlook explorer badly supported by VSTO API

Question

My VSTO Outlook add-in should interact with the recent Office 365 groups Outlook explorer and based on my initial tests the VSTO API is not providing the expected results.

For example, when from a group's explorer window I select an existing conversation I would expect to have that conversation (or the last mailitem in that conversation) returned by the Selection property on the ActiveExplorer object but the count of selected items is always zero. Is there a way of discovering the selected conversation(s)?

Also, when adding a message to an existing conversation, is there are way of knowing what mailitem you are replying to?

Answer 1

VSTO, nor the Outlook object model, doesn't provide anything for that. You may try to use Windows API functions, but there is no trivial to get the job done.

Feel free to leave your feedback at https://outlook.uservoice.com/ .

Answer 2

Unfortunately the Outlook Object Model doesn't currently have any integration with Office 365 Groups. Selection.GetSelection won't work because the view does not support the traditional Conversations view. Selection.Item doesn't work either. The only way to get access to items in a Groups folder is via Folder.Items, but you still can't get access to the selection.