Fix Mac Mail Stuck on Microsoft 365 Sign-In: macOS High Sierra Compatibility
Question details
Users cannot sign in to a Microsoft 365 Exchange account via the native Mac Mail application because the authentication window appears completely blank.
- Product
- Mac Mail / Microsoft 365 Exchange
- Device & OS
- macOS High Sierra
- Scenario
- Attempting to add or authenticate a Microsoft 365 Exchange account within the default Mac Mail application.
- Observed behavior
- The native Mac Mail app gets stuck at the Microsoft 365 sign-in window, and the screen prompting to choose between a work or personal account displays as entirely blank.
Check your current macOS version by clicking the Apple menu and selecting 'About This Mac' to confirm if your operating system meets the latest Microsoft 365 requirements.
Update macOS to a Supported Version
Microsoft 365 modern authentication requires a supported macOS version. Updating your Mac's operating system resolves the blank sign-in screen issue.
Microsoft 365 and Office for Mac currently only support the three most recent major versions of macOS. Because macOS High Sierra is out of this support window, the modern authentication components fail to load, resulting in a blank screen.
Upgrading to a supported version of macOS is the recommended permanent fix, provided your Mac hardware supports a newer release.
Click the Apple icon located in the top-left corner of your Mac's screen.
Select 'System Preferences' (or 'System Settings') from the drop-down menu, then click on 'Software Update'.
If an update is available for your Mac, click 'Update Now' or 'Upgrade Now' and follow the on-screen prompts to install the newer operating system.
After the update is complete, open the Mac Mail app, navigate to 'Mail' > 'Accounts', and add your Microsoft 365 Exchange account again.
Use Outlook on the Web
If your Mac cannot be updated past macOS High Sierra, use a web browser to access your Microsoft 365 Exchange emails as a reliable workaround.
Experience Seamless Productivity with WPS Office on Mac
If you are encountering compatibility issues with Microsoft 365 on older operating systems like macOS High Sierra, WPS Office is an excellent free alternative. It provides a lightweight, highly compatible suite for your documents without the strict OS update requirements of Microsoft 365.
- 1. Visit the WPS Website: Open your browser and navigate to the official WPS Office website to find the macOS download link.
- 2. Download and Install: Download the macOS installer package, open it, and drag the WPS Office icon to your Applications folder.
- 3. Open Your Documents: Launch WPS Office and easily open or edit your existing Microsoft Office files with perfect formatting retention.
Frequently Asked Questions
Why does my Mac Mail show a blank screen when adding a Microsoft 365 account?
This happens because older macOS versions like High Sierra do not support the modern authentication framework currently required by Microsoft 365, causing the sign-in window to fail to render.
What macOS versions does Microsoft 365 support?
Microsoft 365 and Office for Mac typically support the three most recent major versions of macOS. When Apple releases a new macOS version, the oldest of the three loses official support.
Can I bypass the blank screen without upgrading my Mac?
You cannot bypass this within the native Mac Mail app on High Sierra. However, you can access your email using Outlook on the Web via a web browser or by installing an alternative third-party email client that still supports older macOS versions.
