If you're trying to sign in to Microsoft To Do on the web and see a 503 error, this could be related to limitations in the local network or restrictions on a corporate network.
Check with your IT admin to make sure none of these URLs are blocked:
-
.microsoft.com
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.msecnd.net
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.live.com
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graph.windows.net
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graph.microsoft.com
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.office.com
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.office.net
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.office365.com
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static2.sharepointonline.com
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todo-web-endpoint.azureedge.net
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.microsoftonline.com
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.microsoft.io
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.windows.net
-
microsoft-my.sharepoint.com
-
microsoft.sharepoint.com
-
login.microsoftonline.com
