Hello PETER AND HEATHER HULTGREN
Welcome to the Microsoft Community.
I understand that you want to add an outlook alias to your MSN email address. And please correct me if I misunderstood.
You can choose to add a new alias for your account, the same Microsoft account can have multiple Microsoft aliases but still belong to the same mailbox and use the same mail storage. To achieve what you said about emails sent to MSN account name, you can also receive them when you log in to your outlook account name, and vice versa.
You can click this link to log in to your Manage how you sign in to Microsoft (live.com), click [Add email address], create an alias, and wait some time for the alias to take effect (usually within 48 hours for the alias to start working properly). Then use the new alias to log into your account to send and receive emails and more.
Note: You can't add an alias with an outlook.com suffix that already exists. **** Also don’t remove the alias unless you don’t need it anymore. If your email address is an Exchange (e.g. @hotmail.com、@outlook.com、@msn.com), once you remove it you can’t restore it anymore. It means you can’t receive the email others send to this address.
I hope this information has been helpful. If you have any questions. Feel free to let me know if my steps or understanding are wrong or if there is any progress on the issue.
Best wishes
Forry.F - MSFT | Microsoft Community Support Specialist