public async Task <IHttpActionResult> SendMessageAsync(SendMessageBindingModel model)
        {
            var message = new Message
            {
                Id      = Guid.NewGuid(),
                Subject = model.Subject,
                Content = model.Content,
                Files   = model.Files,
                SentOn  = DateTime.UtcNow
            };
            await _messagesRepository.AddAsync(message);

            foreach (var recipientId in model.Recipients)
            {
                var messageRecipient = new MessageRecipient
                {
                    Id          = Guid.NewGuid(),
                    MessageId   = message.Id,
                    RecipientId = recipientId,
                    HasBeenRead = false
                };

                await _messageRecipientsRepository.AddAsync(messageRecipient);
            }

            return(Ok());
        }