@humptydumpty thank you very much.
Here my result and their system reply:
The IP address in question is not currently blocked in our system. Please refer to the email message you received from Microsoft and follow the steps it suggests.
If you're trying to delist an IP address blocked in Hotmail.com/Live.com/Outlook.com, please use the following link.
If you're trying to delist a banned or blocked sender, please open a support ticket from your tenant.