Outlook is replacing Windows' Mail and Calendar apps for security reasons, says Microsoft

The replacement will take place on December 31, 2024.

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Microsoft’s latest decision has sparked some discussion within the Windows community. They encourage users to bid farewell to the well-known Mail & Calendar app on Windows 11. You might wonder why. It is purely for security improvement purposes.

The big technology company is changing its attention towards the new Outlook Web app, and this choice has sparked conversations among many people.

Microsoft’s reason for this shift seems fairly simple: according to the Redmond-based tech giant, the Outlook Web app provides more security than older versions. However, like with any alteration, there are feelings of eagerness mixed with some raised questions.

Outlook for Windows is for everyone – regardless of what email service you use. There is no subscription needed for personal email accounts to use Outlook for Windows and it provides a multitude of features that Mail and Calendar doesn’t include, such as rich message editing, the ability to use Copilot, and reminding you of important conversations. Outlook for Windows also supports Modern Authentication. We are also working on new features in the coming months that will improve Junk Mail filtering and help users better protect themselves from malicious mail. We encourage all remaining users of the Mail and Calendar apps on Windows to move to Outlook for Windows as soon as possible.


Microsoft’s strong promotion of the Outlook Web app is not solely focused on security but emphasizes its economic advantages. Using this application does not incur any cost, as it is entirely free, particularly for personal email accounts.

Nonetheless, there exists an element that Microsoft does not thoroughly clarify: ads. Certainly, unless you possess a Microsoft 365 subscription plan, the fresh Outlook for Windows will incorporate advertisements. It’s a modification with some users contemplating whether the benefit is worth the exchange.

In regard to the ads introduction, Microsoft is certain that the new Outlook has more things like being better and linked with Copilot which is their AI creation. But there’s a problem – you need an internet connection for this app to work well.

When it comes to recognizing its limits, Microsoft tries bringing few offline abilities into Outlook Web app so people can access email, calendar and contacts even without internet availability.

A timer has been set for the Mail & Calendar app in Windows 11, which will say goodbye on December 31, 2024. Microsoft chose to gradually phase out this app because it wanted to provide a superior user interface and features—its old UWP app framework restricted something it felt.

After retirement, you will not find the application in Microsoft Store anymore; it is time for users to welcome new Outlook Web application with open arms.

But Microsoft isn’t just making this change. They are also dedicated to improving the new Outlook Web app by including features that users have been requesting, like COM add-ins and “.PST” file support. This shows how confident Microsoft is about the future of email and calendar management in Windows 11’s new Outlook Web app. So, are you all set to switch, or are you still sitting on the fence?

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