public async Task <IActionResult> SendNews(int newsId)
        {
            var isAlreadySent = _newsLetterService.isSentToUsers(newsId);

            if (isAlreadySent == true)
            {
                return(new OkObjectResult(false));
            }

            var emailList = _newsLetterService.GetAllEmail();

            var newsletter = _newsLetterService.GetDetailById(newsId);

            var emails = string.Empty;

            foreach (var email in emailList)
            {
                emails += $"{email.Email},";
            }

            try
            {
                await _emailSender.SendEmailAsync(CommonConstants.MailAdmin, $"Newsletter: {newsletter.Title}", newsletter.Content);

                await _emailSender.SendEmailAsync(emails, $"Newsletter: {newsletter.Title}", newsletter.Content);
            }
            catch (System.Exception ex)
            {
                return(new OkObjectResult(false));
            }

            _newsLetterService.UpdateStatusSent(newsId, emailList.Count);
            _newsLetterService.Save();
            return(new OkObjectResult(true));
        }