Moving Deleted Items and Other New Outlook Functionality

As everyone knows by now, the new Outlook for Windows is generally available. Normally, this means that a product is feature complete and ready for deployment. Alas. The situation is more complicated because the new Outlook is still well away from a stage where enterprise customers might consider the client to be the finished article. It’s certainly better than the old Windows Mail and Calendar clients, but there’s a reason why Microsoft will support Outlook (classic) until at least 2029.

To Microsoft’s credit, they continue to add features to Outlook, like the update described in message center notification MC896715 (Microsoft 365 roadmap item 413716) telling us that in November 2024 users can drag an item to the calendar icon in the navigation bar to cause Outlook to create a new event. The downside of Microsoft pushing forward with adding features to the new Outlook is that it removes engineering resources from working on stuff that enterprises value, like support for PSTs. I’m sure that creating calendar events from email (which happens today for messages like airline bookings) will be good, but closing the feature gap with Outlook (classic) appears to be much more important.

Controlling Moving Deleted Items from Shared Mailboxes with Outlook Classic

Which brings me to the topic of deleting items from shared mailboxes. Quite why Outlook (classic) insists on moving deleted items from shared mailboxes to the Deleted Items folder in the user’s primary mailbox is beyond me, but that’s the client’s default behavior. The approach might be justifiable if only a single person accessed the shared mailbox, in which case you’d always know where the deleted items are, but the whole point of shared mailboxes is that they’re a resource accessible by multiple people. Scattering deleted items across many different mailboxes just doesn’t seem logical.

Thankfully, a registry setting exists to force Outlook (classic) to keep deleted items in the Deleted Items folder of the shared mailbox. Or rather, in the Deleted Items folder of any mailbox where delegated access allows the deletion of items. The DelegateWastebasketStyle DWORD can be:

Not present: Move delete items to the Deleted Items folder in the user’s mailbox

4: Move deleted items to the Deleted Items in the shared mailbox.

8: As for “not present.”

In most cases, setting the value to 4 is what’s needed. You can update the registry manually (Figure 1) or via group policy. The article cited above contains some caveats that you should be aware of, but in general, 4 works well and is what I use for all the shared mailboxes that I access daily.

Figure 1: Updating the system registry to control the processing of deleted items

No Setting to Control Moving Deleted Items in the New Outlook

The New Outlook is very like OWA and eschews the system registry for application settings. Instead, Outlook settings are stored in hidden items in user mailboxes. This is the right approach because it means that settings are transportable across workstations. In other words, when someone gets a new PC, they don’t need to spend hours configuring Outlook to work the way it did on the old PC. It also means that OWA and the new Outlook share settings, which makes moving to the new Outlook very easy for people who now use OWA.

Good as transportable settings are, it means that the engineers building the new Outlook must track down every registry setting that can be applied to Outlook (classic) and recreate the setting (if required) for the new Outlook. And today, the new Outlook has no equivalent setting to control where messages deleted from shared mailboxes end up. It’s an example of work that needs to be done at some time in the future before Microsoft can retire Outlook (classic).

Debugging the New Outlook

All software is imperfect in some way. Finding glitches in the transition of a client that’s been in use since 1997 is easy, especially during a platform change. Organizations won’t discover if the new Outlook fits their requirements unless people use the client for real work. It’s easy to switch back to the classic client if you find something doesn’t work as expected. And if you do, be sure to let Microsoft know.

So much change, all the time. It’s a challenge to stay abreast of all the updates Microsoft makes across the Microsoft 365 ecosystem. Subscribe to the Office 365 for IT Pros eBook to receive monthly insights into what happens, why it happens, and what new features and capabilities mean for your tenant.