Even though you change the default browser via Settings → Default Apps, Outlook (Microsoft 365) app may always open hyperlinks in Edge. This happens no matter how many different ways you tried to change the default browser.
Cause
In February 2023, Microsoft stated that for Outlook (365) and Teams, the hyperlinks will default to Microsoft Edge regardless of your default browser choice in Default Apps.
If you have a Microsoft 365 Personal or Family subscription, browser links from the Outlook app will open in Microsoft Edge by default, right alongside the email they’re from in the Microsoft Edge sidebar pane. This allows you to easily access, read, and respond to the message using your matching authenticated profile. No more disruptive switching—just your email and the web content you need to reference, in a single, side-by-side view. And we’re always optimizing the sidebar in Microsoft Edge to give you useful content and tools while you’re browsing so you don’t have to toggle back and forth between windows or even other tabs—whether you’re shopping online or working in a Microsoft 365 web app.
In the future, links from your Microsoft Teams messages will also open in Microsoft Edge by default to help you stay engaged in conversations as you browse the web.
However, the users can override the Microsoft-default settings anytime.
Ultimately though, if this experience isn’t right for you, you can turn off this feature the first time it launches in Microsoft Edge, and then in Outlook settings at any time after that.
Resolution
To resolve the issue, change the default browser in Outlook options.
- Open Default Apps in Settings and set the default browser.
Launch Microsoft Outlook, and click File → Options → Advanced.
Under “Link handling”, change the dropdown option for “Open hyperlinks from Outlook in:” to “Default Browser“.
- Click OK.
That’s it. Outlook should now open hyperlinks in your default browser instead of Edge. For more information, see the FAQ section of the Microsoft article Outlook emails open next to web links in Microsoft Edge.