I am helping some people with a spam problem with their windows email server. They are using iMail. Now I want to migrate them to my linux server but need somehting like iMail for them because of their imail structure. they have a system where everyone has a firstname.lastname@example.org
alias - then mailing lists are populated with those alias. You cannot even create or populate a list with anything else but alias that are created first. So in other words the "forwarders" and the "mailing lists" work together. Is there a linux based contribution that accomplishes this??