The Hidden Knowledge Mangement system.
I’ve recently read Datawocky’s article on Replacing Email with blogs, wikis and IM. Its has some good ideas however the devil is in the details. The advantage of email is that it is convenient for the creator. If it is not convenient for the creator then they are less likely to create/send the data. It might be correct that the 3 system approach would be easier to retrieve data but if it reduces the amount of electronic data then it only hurts the communications.
I think a better approach would be to have special email addresses that automatically publish the content and responses of the emails themselves. We see this for mailing lists on the internet today. Any email written to low level groups in your organization could be published to an internal website. However this does not solve the multiple document revisions being passed back and forth over email problem. To handle documents that are passed back and forth I would argue that better group editing tools would be better such as google docs but for the intranet company. Nobody likes downloading documents to their local machine unless they are taking it off line.
A little scripting on the email server side could eliminate this issue. Whenever a document is emailed out it could be replaced with a link to an editing tool with the document saved on the server side.
Along with this companies should be smart about how they define email addresses. People on the helpdesk should not their person specific email address to customers. Instead they should give a generic email address that can be reassigned to someone else after the original person leaves for a new job. How oftern have you used your email as a datastore. A person that has been with the company for a decade probably keeps a significant amout of his information in his email. A resource a lot of people never look at after the original person leaves.