I am not an expert on these things, but you might be able to at least solve the symptoms of this problem but changing the MAILTO variable in /etc/e-smith/templates/etc/crontab/template-begin from 'root' to 'root@home'. (Make sure you run '/sbin/e-smith/expand-template /etc/crontab' after that, to propagate the changes.)
I am not sure what would cause the problem, the only think I can think of is that 'home' is not a valid domain name as there is no top level domain specified, but again this is just speculation.
Hope this helps, as this is the only thing I can think off,
Kees