Using older versions of Outlook for Mac for personal email and calendar
Heelo
What you can do is to give your account a different alias, then delete the current hotmail email address. This way it is still the same Microsoft account, nothing under that account changes.
Sign into your personal account via this link: https://account.live.com
Go to Your Info > Sign in preference, Add an alias.
You have two options here:
Create new: this will allow you to use the native domain outlook.com to create a new alias.
Add existing: this will allow you to add a 3rd party email address, such as yahoo, gmail, as long as they are not already associated with another Microsoft account.
Once added, make this new alias your primary alias, then you can delete the other email as alias, and that email is free from this Microsoft account instantly. If people email the old alias/email address, it will not come through anymore.