in my account, i had an OLD domain that i now deleted it.

I added the new domain, i only want one email, a personal one, no groups, no other users

I created the user, user@newdomain.com

BUT in control panel -> mail accounts -> there is my main account and there is a mailbox alias that has my OLD domain email...when i try to delete it, it says:  The input passed is invalid

how can this be fixed?