reuse of deleted email address

I've deleted my alias acc but want to use it again but as a separate account, I've tried creating a new account but it says - Someone already has this email address. Try another name or claim one of these that's available but it's not as I've deleted it... Do I have to wait a certain amount of hours or days until I can reuse it again and if yes then how will I know when it's available as I don't want someone else to get it before I do