I am still convinced, that one way to foster professionalism in working e-mail and to facilitate collaboration would be to use e-mail as the interface for a content management system:

- incoming e-mails are categorized by organization sending/topic (until a project can be associated)

- all attachments are stripped off and stored on the server using a hierarchy which the recipient is prompted to update

- outgoing e-mails are treated in the same fashion in reverse, so a link to a file on a server is moved to the CMS and then included as a clickable link

(probably employees would have to have a separate company-sponsored e-mail for insurance correspondence)