Dear Zzz89
Good day! Thank you for posting to the Microsoft Community. We are happy to help you!
First of all, we regret for the inconvenience caused to your work. Based on your description, if you're using a Microsoft 365 Business account, please first kindly contact your administrator to help you restore the email feature. Plus, they can do more to help protect your account. Please kindly contact your organization's administrator to follow the steps in this document: Responding to a Compromised Email Account - Office 365 | Microsoft Learn
At the same time, if your account was surely hacked, I recommend that you try the following to check the results on how to secure your account:
By the way, due to some technical and permission limitations in our forum, we are unable to provide you with telephone communication support, in order to better help you and not waste more of your time, it is recommended that you contact our 365 support team directly by phone and they will provide you with further assistance. For details, please kindly refer to this official documents: Find Microsoft 365 for business support phone numbers by country or region - Microsoft 365 admin | Microsoft Learn
Note: Please note that you need to call the hotline on weekdays, (9am to 5pm, Monday to Friday) sincerely apologize and thank you again!
During the phone call, press "1" as a business email user and press "1" again for technical support. You may be asked for some information for verification, such as account or subscription information, organization details, phone number.
Here are other global support phone numbers: Global Customer Service phone numbers - Microsoft Support
Note: The Microsoft Technical or Business Support Engineer may collect alternate email address information to assist with the verification process.
Meanwhile, if you still need further help, then please kindly tell me more details: such as yourtype of account(business account within business subscription/outlook.com/hotmail.com/live.com/msn.com/imap account/pop account) and I will try my best to do more research and tests, thanks.
Thank you in advance for your understanding! Your patience and cooperation will be greatly appreciated. I hope all the best!
Sincerely
Kerry Chen | Community Moderator