Use different mailing lists for successful and failed CI build
Use the field "notify_suceeded_email_to" to set the mailing list for successful CI build and use "notify_failed_email_to" to set the mailing list for failed CI builds.
In case one or both these fields are not set, use as default the mailing list set by "notify_email".
Also add the field "notify_email_to" that will be used instead of "notify_email".
Set "notify_email" to be used as fallback for "notify_email_to".