setReplyToList(replyToList) {
    if (this._doArrayCheck('replyToList', replyToList) && replyToList.length) {
      if (!replyToList.every(replyTo => replyTo && typeof replyTo.email === 'string')) {
        throw new Error('Expected each replyTo to contain an `email` string');
      }
      this.replyToList = replyToList;
    }
  }
Set the replyToList from email body