Would you recoomend this project?
PloneMailList is a Plone product (V1.1 pour Plone2.5 et V2 pour Plone3) able to manage standard mailing lists over Pop or Imap Protocol. Messages are stored as Plone contents and can be browsed and searched through the Plone interface.
You can download file releases of PloneMailList project from List of release files
System RequirementsOperating System: OS Independent
List of release files