Notification emails for success

Hi
Just trying out TeamCity and pleased with how easy it is to get going. Just missing one piece...
When a build fails emails are sent out - our developers are getting these. How can I get an email sent if a failing build has been fixed?
ie the flow would be
build fails -> emails sent -> developer fixes and checks in -> build kicked off -> build passes -> Now I'd like an email saying its been fixed.

Of course I don't want emails sending each time the  build passes - only when the previous build failed and the  current build passes

Many Thanks

Mike