net-libs/courier-authlib-0.69.0-r1 has the following lines in its .service file at /lib/systemd/system/courier-authdaemond.service: ExecStart=/usr/sbin/courierlogger -pid=/var/run/authdaemon.pid -start /usr/lib/courier/courier-authlib/authdaemond ExecStop=/usr/sbin/courierlogger -pid=/var/run/authdaemon.pid -stop /usr/lib/courier/courier-authlib/authdaemond /usr/lib/courier/courier-authlib/authdaemond does not exist with this version however. The file has been moved to /usr/libexec/courier-authlib/authdaemond.
I don't use a systemd-based system, but are you sure that file got installed by the ebuild? We have nothing in the ebuild indicating it installs a service file. There's a service.in file in the courier-authlib source and it may be that this gets installed automatically, but it then should know where its default path is. But my first suspicion would be that you installed this manually from somewhere? (If not please attach a full build log.)
I tested this now in a Gentoo/systemd chroot and neither courier nor courier-authlib install this file, so I can only assume you got it from elsewhere. Please re-open with more info if you believe this is a bug in the package.
