Having problems updating old Y! account - more specifically my name?

I made an account a long time ago under a different alias when I needed some privacy. I recently consolidated my email to only that account, and I'm still showing up under my old alias "Hope Smith" in other people's inbox. I've already tried to change it by going into "My Account", and it SAYS I am who I need to be, but it hasn't updated as far as outgoing mail. I don't remember if I was in the old 360 stuff; that could be the problem. How do I fix this? My relatives want to know why I'm "Hope Smith" :)