I get a number of errors when starting gnumail, and no text is displayed.
Created attachment 16932 [details] log of startup/quit of GNUMail.app
I suppose I should have pointed out that I'm using version 1.1.0, and couldn't get 1.1.0pre1 to build at all. I'm using gnustep-back v0.8.8.
You are probably just missing a font set. A set of nfonts can be found at http://developer.linuxstep.org/downloads/basic_fonts-2.tar.gz (legality uncertain, licensed under the GPL though) I do not use the libart backend nor do I have a proper procedure for it's setup and proper use.
0) There are newer packages 1) You are definitely missing a font set, or have not configured which fonts to use with the art backend - if you're using the new ebuilds, you can "emerge -pv gnustep-back-art" and then run "/usr/GNUstep/System/Tools/Gentoo/config-gnustep-back-art.sh" to set your fonts.