Let me clarify -
From the end user's view, we want them to just receive and send emails to email@example.com firstname.lastname@example.org email@example.com etc.
As far as what subdomain.domain.com we use ... I don't care. But it seems like when I create listsub1.domain.com and try to setup a second list, it trys to do everything at listsub2.domain.com