Hi, I'm John!
No, you do not need to purchase Microsoft 365 to keep using your Hotmail email account. Hotmail/Outlook.com email accounts are free and will continue to work without a Microsoft 365 subscription.
Microsoft 365 is only required if you want premium apps and services, such as the desktop versions of Word, Excel, PowerPoint, or extra OneDrive storage. Your email itself does not require a paid subscription.
It’s possible someone misunderstood this, or it may have been a scam if they were asking you to pay directly.
To help narrow down the issue:
- Where were you told this? Was it an email, phone call, or a website?
- Did someone ask you to pay or provide account details?
The official Microsoft address for account security notices is:

Reference: "Can I trust email from the Microsoft account team?" https://support.microsoft.com/account-billing/can-i-trust-email-from-the-microsoft-account-team-685fd302-f52f-1a9f-cc13-065dec46fe25
To be safe, I recommend not to click on any links or download anything from that email.
Click "Add comment" to let me know.
Regards,
John J.D.