message: Add test environment.
diff: @@ -19,6 +19,10 @@ class EmailService {
  };
  constructor() {
  + if (process.env.NODE_ENV && process.env.NODE_ENV.includes('test')) {
  + this.mailTransportConfig.streamTransport = true;
  + }
  +
  // define endpoint and login-credentials for smtp server
  if (config.mailSMTPServer === undefined) {
  this.mailTransportConfig.service = config.mailProvider;
  