Using New Outlook on Windows for personal email, calendar, and contact management
Hi!
Where exactly are you seeing this email address? Do you see it when sending an email, receiving one, or logging in?
It is likely that your own contact entry is saved incorrectly. To verify this in the New Outlook, click the People icon (your contacts) > Search for your contact (you can search by your name or the email address itself) > Open the contact and check if the email address listed there is incorrect.