I switched to the Courier IMAP server, and I found that all the
articles have "0 lines" in the summary.

The attached patch will fix this. Can someone please apply?

2000-04-10   Daiki Ueno  <ueno@unixuser.org>

        * lisp/imap.el (imap-body-lines): Check Content-Type: of the
        article case insensitively.