With creating links working in Rmail, now I see that following links
fails with the error "Message not found".

The error comes from the use of the function widen in
org-rmail-follow-link. In an RMAIL buffer, the widen function only
widens to the current message. The function to widen to the entire
buffer is rmail-widen.

The attached patch replaces widen with rmail-widen and also removes the
following two lines (added by Bastien as part of the previous patch re
Rmail), because rmail-widen already displays full headers, so testing
and toggling them on has no effect.

GNU Emacs 24.1.50.1 (i686-pc-linux-gnu, GTK+ Version 3.4.2) of
2012-07-29 on doubah, modified by Debian

Org-mode version 7.8.11 (release_7.8.11-392-g9dae6f-git @ mixed
installation! /usr/local/share/emacs/site-lisp/ and
/home/tftorrey/.emacs.d/src/org-mode/lisp/)

Best to all,
Terry
-- 
T.F. Torrey