Event Log email software?

We have discovered that a mirror on the server is off line.
It has been off for some time.

We think we should get some email software that will find disk errors
for example and then email us a warning. Is there any free software
that would do this. It really doesnt need to be complex, just look for
a few errors and then email or start beeping even the server speaker.


I know if we had a hardware raid with this built in then this would do
this but we dont and are not going to change at this point.

thanks