I was able to merge in the changes from the above referenced ashlux branch into the most recent 2.15 version with 3 minor conflicts. I can confirm that patch works to allow only a single e-mail from the parent node (and an option to specify all configurations or both parent and all configurations).
Unfortunately when using the parent e-mail only, tthe e-mail does not contain any of the build log information from each configuration and requires a visit to the jenkins build page to see which configurations actually failed followed by several clicks to dig down to the build logs.
I think a better approach would be to allow all individual e-mails from each configuration to be aggregated into a single e-mail that contains all of the information from each individual configuration.
We have a large number of configurations that we perform integration builds on via a Matrix project. Getting bombarded with 20 e-mails because of a typo or missing prototype which causes the build to fail on large numbers of configurations is a little bit overkill. Generating a single e-mail with an aggregation of what would have been the individual e-mails is ideal.
Since this suggestion is not the same as this ticket, I'm going to create a separate request ticket for this functionality.
That said, thanks for posting the patch as it definitely helps clean up the barrage of e-mails we are getting even if it means we have to do a few more cumbersome clicks to get to the configuration failure information and logs.
This is a patch for 2.10 version