Make Outlook add-ins working with Office 365 shared mailboxes

Question

I am building apps with the new technology of Office add-ins (formerly app for Office).

The add-ins activate well when registered globally for the Office 365 tenant or individually by user (mechanical gear > manage add-ins).

I would like my add-in to work with Office365's shared mailboxes. The add-ins do not load in Outlook desktop or in OWA when the shared mailbox is open alone.

However, I managed to make it work when setting the shared mailbox as a shared folder displayed under my primary mailbox, as explained here (see picture below). It is better than nothing but not an acceptable solution, I would like my add-ins to be displayed when consulting my mailbox in Desktop client and in OWA when using the "Open another mailbox" (see link above).

My question is then: how to make add-ins working with shared mailboxes? A possible solution is: a shared mailbox seems to be related with a special kind of user. Would it be possible to install the add-in for this special user in order to have the add-ins always working with shared mailboxes?

Edited: Not supported for now. I created a feature request in Office365 User Voice. Consider bringing your vote to it.

Solution 1

Outlook add-ins are not supposed to activate outside of your primary mailbox. This is intentionally disabled. What you're seeing with it displaying when opened under your primary mailbox there Benoit is likely a bug.

Solution 2

There is a new feature request to cover this functionality.

This feature request has theoretically been implemented and is in public preview.

Theoretically if you add the following under <DesktopFormFactor> it enables this feature:

<SupportsSharedFolders>true</SupportsSharedFolders>

However, people are having issues with this throwing Schema errors. See GitHub or StackOverflow. (NOTE: StackOverflow has a solution, but I didn't find it actually worked).

It maybe there is some undocumented magic so it could work now.