Mail from Apache ?

I'm getting some mails send from the Apache I administer.
Like :

Subject: Some Subject
From: Apache <[email protected]>
Date: Fri, 20 May 2005 10:08:12 +0800
To: [email protected]

This is the body



this bugs me a bit; i'm sitting with a fully updated tao here:
# yum update
Gathering header information file(s) from server(s)
Server: Tao Linux 1.0 - i386 - Base
Server: Tao Linux 1.0 - i386 - Updates
Finding updated packages
Downloading needed headers
No Packages Available for Update
No actions to take

I wonder how this works, and how I could prevent someone from sending
mail !

Uwe