This script will be run prior to sending the email to allow
modifying the email before sending. The MimeMessage variable
is "msg," the build is available as "build", a logger
is available as "logger". The trigger that caused the email
is available as "trigger" and all triggered builds are available
as a map "triggered."
You may also cancel sending the email by setting the boolean
variable "cancel" to true.
You can set the default pre-send script here and then use
${DEFAULT_PRESEND_SCRIPT} in the project settings to use
the script written here.