The portage version net-mail/mboxgrep-0.7.3 is getting old. Please, update mboxgrep to the new version. Reproducible: Always Steps to Reproduce: 1. 2. 3.
Created attachment 16580 [details] ebuild for mboxgrep-0.7.9 My ebuild for net-mail/mboxgrep-0.7.9
Okay, verified to work. Although, RDEPEND should not be set DEPEND (see the developer docs). It was also this way in the original 0.7.3 ebuild, so I perhaps you're not to blame for that :-).
bumped with the RDEPEND fix :9