Odd message from cron daemon

[Anthony Atkielski]

I get an e-mail like the following every eleven minutes on my test
system:

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From operator at contactdish.atkielski.com Sun Feb 27 16:55:00 2005
Date: Sun, 27 Feb 2005 16:55:00 +0100 (CET)
From: operator at contactdish.atkielski.com (Cron Daemon)
To: operator at contactdish.atkielski.com
Subject: Cron <operator at contactdish> /usr/libexec/save-entropy
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin>
X-Cron-Env: <HOME=/>
X-Cron-Env: <LOGNAME=operator>
X-Cron-Env: <USER=operator>

This: not found

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What does this message mean?  I've never seen it on my production
system.

-- 
Anthony