E-mail notification are currently broken in our packages since the binary for @MAIL_PROG@ are not replaced during build to actual path to mail program.
The mail program should also be a dependency for the package
After installation of Naemon 0.8.0 the following file are affected: /etc/naemon/conf.d/commands.cfg
fixed with naemon/naemon-core@353c912
I just had this issue in naemon 1.0.0-1.el6.x86_64, built from the dev instructions. I did move my config over from a previous naemon install, so maybe some config setting got lost?