There is a new version of exmh out 2.7.0 http://www.beedub.com/exmh/. An ebuild for that would be swell (Btw, I'm an exmh hacker, and could consider contribing to exmh ebuilds. What's the process for that?) Reproducible: Always Steps to Reproduce: 1. 2. 3.
Ebuild for 2.7.0 is in portage now. Thanks for reporting. As for the contributing to ebuilds, read ebuilds and try to understand them. Developer documentation on http://www.gentoo.org might help you with it.