Hi Jason,
Thank you for reaching out. My name is Leo, a user just like you. I'd be happy to help you with your concern.
This seems to be a rare issue. Can you confirm if the email you received is coming from Microsoft or OneDrive? Usually, emails coming from Microsoft will bear the domain "@microsoft.com". Since you have also stated in your description that there is a discrepancy of information with what is showing on your OneDrive, it might be that there is something wrong. To further check the account storage, it is best to log in via the OneDrive online version at www.onedrive.com, then sign in to your account. From there, you will be able to see the correct storage space. If it is not the same as what you are receiving in the email, I recommend ignoring it or moving it to spam since it might be a phishing email. In case you still need further assistance, please don't hesitate to let us know. We, the community users, are always here to help. Thank you!
For more information regarding this kind of issue, you may access the link below:
https://support.microsoft.com/office/0d882ea5-eedc-4bed-aebc-079ffa1105a3
Your understanding and patience will be highly appreciated. I hope I provided a helpful information regarding your concern! Let me know if you have any further questions. Be safe always!
Best Regards,
Leo