mailtool

mailtool was an XView program in three parts: a list of the messages in the inbox, a reading window and a compose window, plus an attachment pane at the bottom into which files could be dragged from filemgr or dragged out onto the desktop. Messages were read from the ordinary mbox file in /var/mail, so the command-line mail and mailtool saw the same data. Iconified, it showed a mailbox whose flag went up when mail arrived, in direct descent from the SunView program of the same name.

Sun solved attachments its own way, before MIME: a message body split into sections with headers such as X-Sun-Data-Type, X-Sun-Data-Description and X-Sun-Content-Lines. It worked beautifully between two Sun machines and gave everyone else a message full of gibberish, which kept postmasters busy for years; mutt still carries code to unpack the format. Later versions in Solaris 2 learned MIME, and dtmail, Sun's contribution to CDE, read both formats so that old mail would not become unreadable when OpenWindows was retired.