static create(data) {

    //Array?
    if (Array.isArray(data)) {
      return data
        .filter(item => !!item)
        .map(item => this.create(item));
    }

    //Already instance of Mail class?
    if (data instanceof Mail) {
      return data;
    }

    //Create instance
    return new Mail(data);
  }
Create a Mail instance from given data