I use Maven+TestNG auto-tests run by Jenkins. I know that the is a token for failed tests like ${FAILED_TESTS} but it also includes long stack-trace which is difficult to read.
So I want Jenkins to send email like this: Run: 10, Failed:2, Passed: 8
It looks like you could customize the email template by using the Email-ext plugin and Jelly templates.
See http://softwaretestautomationnotes.blogspot.com/2011/07/customizing-post-build-email.html for an example of this.
I don't know of any way to do this out of the box.