Deletion of Columbia MM

Comment: Mainly for historical value, to document how email clients didn't start out as Netscape, Outlook. Articles like this show (or with some editing and a nav-box, would) the gradual evolution of clients. Since this was co-written by Mark Crispin I'd like to link the articles. I added a ref to rfc 1203 which mentions Columbia MM. I don't think  is a problem and this article can be built upon and wf'd to help document the history of email
Stance: keep
Cited policy: Wikipedia:Reliable sources (WP:RS)