
Hi @Luke Zheng,
You can immediately submit a request for a correction. Microsoft Defender SmartScreen has a built-in, web-based feedback system in place to help customers and website owners report any potential false warnings as quickly as possible.
In Microsoft Edge, from a red warning, click More information then Report that this is not a scam site. This will take you to a feedback page where you can indicate you are a site owner or representative. Follow the instructions and provide the information on this site to submit a site for review.
Once a dispute is submitted, a team of graders inspects the site in question. All disputes should be submitted through the website reporting process to ensure the quickest resolution.
The block probably might caused by the certificate, if you ask users for personal information, use HTTPS with a valid, unexpired server certificate issued by a trusted certification authority.
For more information, you can refer to the Microsoft Defender SmartScreen Frequently Asked Questions
Best regards,
Wenying Lu
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