Back in September of 2025, Microsoft announced that it would block the installation of its lightweight Outlook version, dubbed "Outlook Lite" as it was deprecating it. It was a cool application for sure that was released just three years before. It weighed in at just around 7.5 MB and was a massive success.
Interestingly, that was not the only lightweight Outlook version that has existed, and today, Microsoft has announced that it is killing off the original Outlook Web App (OWA) Light on Exchange Servers soon.
For anyone who may not be familiar, the OWA Light was first introduced by Microsoft way back in September of 2006, which is almost 20 years ago. This was the lighter version compared to OWA Premium. As such, it brought in a new redesigned cleaner and simpler UI and promised faster logon times for slow connections and would work across a diverse set of OS/Browser combinations, including Windows Vista, XP, 2000, ME, 98, Mac OS X, and Linux, and browsers like Firefox, Safari, Opera, Netscape, and Internet Explorer (IE) versions IE7, IE6, IE5.5, IE5.01, and IE5.2 on Mac.
The feature was originally built for older web browsers and low-bandwidth environments, but the web has visibly changed dramatically over the past two decades. And since modern browsers now support the full Outlook on the web experience with better performance and compatibility, Microsoft feels this makes the separate lightweight mode increasingly unnecessary.
The change will arrive with the next planned Exchange Server Cumulative Update, currently scheduled for August 2026. Once admins install the update, OWA Light will be disabled by default across their organizations. After this, users attempting to access the lightweight interface will instead be redirected to the standard Outlook on the web experience automatically.
It is noteworthy that Microsoft had already announced the deprecation of OWA Light back in August of 2024, so we knew it was only a matter of time before the app was done away with forever. You can find more details about the upcoming change in the blog post here on Microsoft"s official Tech Community website.