Today I was greeted with interesting message under my notification which was surprise to me. While tweaking my profile to change the phone no,I found a renaming username feature which allowed me to change the username . I also changed my hotmail email to Outlook which really offers no new feature as we all are using the same email service. But Outlook looks cliché than hotmail which sounds old.
After renaming the username, the old email address becomes the alias of the new email address. The emails of the old username are moved to the folder of old email address and the inbox of new username appears on the screen. A boon for those who hastily created the email id but are not happy with the username. And an option which other email service providers must include .
Source Microsoft Account