Hey there, Stefan De Machtige
This will depend on whether you are using a domain email address with Outlook. If you have a personal domain email address that is tied to the tenant, and have a Microsoft 365 business plan, then deleting the tenant could delete the email address.
However, if you have a personal Microsoft account that you have used to create your tenant on Azure. Deleting this tenant won't affect your Outlook account as the account is different. When you sign into Azure using a personal account, it takes the email address and makes it into a business email. For example, it may be that your email address is @hotmail.co.uk which will be given a examplebobjones_hotmail.co.uk#@yourtenant.onmicrosoft.com which is how your account is able to access Azure.
You can find out more about tenants being removed/deleted here: https://learn.microsoft.com/en-us/entra/fundamentals/inaccessible-tenant
You can find this question someone asked about their personal account being removed/deleted when they delete their tenant here: https://learn.microsoft.com/en-us/answers/questions/2258321/how-do-i-remove-a-tenant-and-permanently-delete-my
Hope this helps,
Nathan