It seems as if environmental variables don't work with the emailext plugin. I am using declarative pipelines, but regardless of what I try the ${ENV, var=""} returns nothing. I can see that the double quoted subject "$VERSION" is correctly replaced and other tokens work such as single quoted '${BUILD_STATUS}' work, but '${ENV, var=""}' and '${ENV, var="VERSION"}' are always replaced empty. Same occurs with variables such as $PATH.

pipeline {
  environment {
    VERSION = "1.0.0"
  }
 
  // ...
  // stages
  // ...

  post {
    always {
      emailext (
        to: 'DEFAULT_RECIPIENTS',
        subject: "$VERSION",
        body: '${ENV, var="VERSION"}'
      )
    }
  }
}

Regards

Erik Hughes