[rancid] RANCID Log Messages: "sendmail: not found" with no mailed diffs

[Traiano Welcome]

Hi List

I've been getting the following log messages in my rancid logs recently, 
along with no emailed diffs (although the cvs updates are happening):

---
/usr/lib/rancid/bin/control_rancid: 397: sendmail: not found
---

What might the cause of these messages be? As far as I can tell, it 
looks like control_rancid is not finding any diffs to mail when called, 
even though running "cvs log <filename>" shows the most recent committed 
changes correctly.

Thanks,
Traiano