cron job for tripwire always sends mail

["Karen Ellrick" <k-ellrick sctech co jp>]

I recently installed Tripwire 2.2.1 (for those who don't know, it's a
program that keeps a database of file signatures and can alert you if
something has been changed without your notice - great for guarding against
rootkits and other hacking) and added a file to cron.daily to run an
integrity check.  Within the Tripwire software itself there is the capacity
to mail a copy of the integrity check report to an interested party if
something has changed, and that is working fine.  But for some reason the
cron daemon also sends mail with a copy of the Tripwire report every night,
even if no changes were found.  None of my other cron jobs generate mail, so
I don't know why this one does.  I don't want to remove the MAILTO=
definition in etc/crontab, because I would certainly want to be notified if
something failed to work (I assume that in that case, the cron daemon would
send mail - everything currently works, so I don't know for sure).  Anybody
know why it is sending mail, or better yet, how I can make it shut up about
successful running of a Tripwire check but still have it alert me if any
cron job fails?

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Karen Ellrick
S & C Technology, Inc.
1-21-35 Kusatsu-shinmachi
Hiroshima  733-0834  Japan
(from U.S. 011-81, from Japan 0) 82-293-2838
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