Hi guys,

I am pretty new with the FreeBSD UNIX flavour, and I met something weird in
my new job. I received two email daily at 2:00 pm from Charlie Root (I
understand it is FreeBSD's root account). But the thing I don't get  is I
cannot find how the email is generated. There is nothing in cron job, and I
didn't see any daemon is being likely doing this sneaky trick.

Any idea would be appreciated!

comp.unix.bsd.freebsd is not widely propagated, so you won't
necessarily get much help here (in comp.unix.bsd.freebsd).
See http://www.freebsd.org/support.html for better ideas...
[followups redirected accordingly]

It's crontab, all right.  One of the standard crontab jobs is periodic(8).