Only recently it got patched because it apparently puked out the root password. Secondly, Roundcube is horribly outdated and not easily to upgrade. It also still has the white-space bug, preventing you from logging in.
If you finally fixed the bug and managed to log in, you can’t send any email. It’s supposed to run out of the box and it only does it partially. The interface is easy and once it works, it does the thing. But generally, it’s poorly maintained.