If you run Outlook for Windows during an Internet access outage, then instead of opening a window, it instantly pops up an error message then quits. The error:

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Connection Error

A connection to the internet could not be established. Please connect to the internet and restart the application.

[_OK_]

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Boy, destroying the Mail app built in to Windows & replacing it with a PWA worse than Electron was sure a good move and worth it.