On August 1, 2024, the new Outlook for Windows (aka “the Monarch client” reaches generally available status (see Microsoft 365 message center notification MC810420). It is however important to mention that “generally available” is only a point in the software lifecycle.
Although the new Outlook for Windows is now fully supported for deployment in production, it lacks many significant features compared to the classic Outlook. However, if your users prefer the Outlook Web App (OWA), it may be a good idea to ask them to switch, as they won’t see much difference and can provide your organization with a valuable test group to measure progress for the new client
What was behind the ‘One Outlook’ Vision?
The new vision for the Outlook for Windows project, known as “One Outlook”, was introduced at the Microsoft Ignite 2020 conference. The goal is to unify the various Outlook client versions into a single codebase that can run on multiple platforms. The rationale behind ‘One Outlook’ is that creating a unified multi-platform client will accelerate the delivery of new features to customers. It is evident that Microsoft can innovate more easily in Outlook on the Web (OWA) than in the classic Outlook application. The classic Outlook architecture, dating back to 1996, has remarkably adapted to the changes in email usage and volume, but it shows signs of strain at times.
The One Outlook vision is an attractive engineering strategy that allows Microsoft to escape the complexities accumulated within the Outlook classic code base since 1996. It eliminates the need to maintain and develop multiple code bases, resulting in a more cost-effective engineering investment. The new Outlook for Windows serves as the foundation of the One Outlook vision, with variants replacing OWA for Exchange Online and the Outlook browser client for Microsoft’s consumer Outlook.com service. To fully realize the One Outlook vision, a Monarch variant will also replace the current Outlook for Mac.
The new Outlook has yet to surpass the feature set of the classic Outlook. Despite the announcement of the One Outlook vision four years ago and the public beta two years ago, progress has been really slow. Microsoft has replaced the Windows Mail and Calendar clients with the new Outlook for Windows in late 2023, leading to backlash and concerns about data synchronization from users with mailboxes hosted on outdated servers. However, there are many free email clients available if users are worried about Microsoft accessing their emails. To fully utilize the features of a modern client, users may need to compromise when their mailbox is hosted on a server from the 1990s.
When will it be available?
Microsoft initially outlined the timeline for the availability of the new Outlook for Windows in March 2024 (New Outlook for Windows: A Guide to Product Availability – Microsoft Community Hub). The key points are that general availability does not mean mandatory use of the new client, and Outlook classic will be supported until at least 2029. Over the next five years, the new Outlook for Windows will progress from an opt-in stage to an opt-out phase, and then to the final cutover from classic to new. During the opt-in period, tenants can control access to the new Outlook for Windows client by hiding the slider displayed in classic Outlook, but the controls are likely to change during the opt-out phase.
Microsoft was once very forceful in requiring the use of the new Outlook for Windows, even making it a prerequisite for Copilot for Microsoft 365. However, over time and with customer backlash against the mandatory use of the new Outlook for Windows in their Copilot adoption campaign, their perspective has evolved.
The transition is challenging
Microsoft understands that Outlook classic users will not switch until the new Outlook is functionally equivalent. Many changes have occurred over the past year, and users should test the currently available code to check if the new Outlook meets their expectations. If not, users should provide feedback through the Outlook feedback portal (Feedbackportal), as Microsoft responds to feedback posted there, even if the responses are often delayed.
Two important areas are offline working and PST support. While PSTs are disliked, they are useful in certain situations, such as transferring the results of an eDiscovery investigation to an outside expert for review. While in the past, small mailbox quotas necessitated storing all emails in a PST file, this is no longer necessary with the generous 100 GB Exchange Online mailbox quota. However, this habit persists, creating a risk of data exfiltration when employees move between companies. The solution is to use sensitivity labels to apply rights-management based encryption to sensitive emails and documents, ensuring former employees cannot access the encrypted content.
Microsoft has announced that offline support for mail actions and compose will be available in late June 2024 (message center notification MC798674). The worldwide deployment was initially scheduled to be completed by late July 2024 but has been slightly delayed. Users can configure their offline settings in the General settings of the new Outlook application.
The initial set of offline functionality (Switch from working offline to online – Microsoft Support) is unlikely to satisfy Outlook classic enthusiasts, as it may not be as comprehensive as the drizzle mode synchronization model introduced in Outlook 2003 and still used today. After two decades, the next generation of Outlook for Windows appears to be significantly behind in addressing a problem that was thought to have been resolved long ago. It seems that it takes time to teach One Outlook how to synchronize effectively…
