What happens to my yahoo mail if I repoint my domain name?

I'm asking this on behalf of a client. If they have whatever.com that they registered with yahoo and are receiving emails at joe@whatever.com, if that domain name is repointed to Bluehost, will they still have access to the old yahoo emails via their yahoo account? I understand the new emails will go to the new server, I'm interested in what happens to the old emails. Thanks!