Hi Team, Outlook Add-In is not enabled when the user has selected a mail (not yet read) while the reading pane is off. As a result, while developing any custom add-ins, we are not able to retrieve t...
The Ribbon button for Viva Insights (or any add-in) is not displayed when the Reading pane is off - please check again. Regardless, there is unfortunately no way to do what you want to do. Users must always activate an add-in manually when reading messages, and then they can pin it so it stays open. Only compose scenarios allow for an add-in to run script through event-based activation, but even those cannot automatically open a task pane.