logging, can one get it to email messages over a certain level?

[tinnews at isbd.co.uk]

I'm sure this must be possible but at the moment I can't see how to do it.

I want to send an E-Mail when the logging module logs a message above
a certain level (probably for ERROR and CRITICAL messages only).

I.e. I want some sort of hook that will be called when these messages
are logged (I can do the sendmail bit OK, I've got code that does that).

-- 
Chris Green