Microsoft Editor is an AI-powered writing assistant and grammar checker from Microsoft, similar to Grammarly and other services. It's already integrated in some Microsoft apps, like Word, but now it's rolling out to all Outlook applications.
Microsoft Editor was already available on the web versions of Word and Outlook (with a Microsoft 365 subscription), as well as Word for Windows. There's also a browser extension for Chrome and Edge that adds Editor to text boxes in web pages, much like Grammarly's extensions. Now it's expanding to Outlook on Windows, Mac, iOS, and Android.
No matter which Outlook app you use, Microsoft Editor will offer spelling, grammar, and writing style suggestions in supported languages --- once it rolls out, anyway. If you prefer your device's own grammar tools, you can turn off Microsoft Editor in the app settings. It's still not available in Outlook.com on mobile browsers, or the Mail app on Windows 10 and Windows 11.
Microsoft says spell checking and basic grammar checking will work with free Outlook.com accounts, but more advanced features will require an active Microsoft 365 subscription. The advanced features are also enabled for education, business, and enterprise accounts, so if you use Outlook through a school or company email, they should be available there too (unless the administrator turns it off).
Microsoft is also working on a completely new Outlook app for Windows, based on the web app, which doesn't seem to have Microsoft Editor integration yet. However, that app is still in preview and is missing many more important features (like offline support), so that's not too surprising. Microsoft also says more Editor features are coming to Outlook, but the company didn't provide a timeline.
Source: Microsoft