My Outlook add-in has a handful of user preferences: which tab to open by default, language, a “don’t show this tip again” flag. Small stuff. A single JSON blob. So where do you put it? localStorage is per-device, per-browser, and mobile WebViews evict it whenever they feel like …

In my last post I showed how declaring a low Mailbox requirement set in the manifest got my Outlook add-in to show up on mobile. Great. Button’s there, task pane opens, everything looks alive. Then the user taps “Archive to SharePoint” and the whole feature stands on one API: …

This is the third post in what accidentally became a trilogy about getting my Outlook add-in to work on mobile. Post one made the add-in visible on the phone. Post two made it functional by falling back to a Microsoft Graph call when getAsFileAsync wasn’t there. And in that second post I wrote …