public async Task RunAsync()
{
var messageRepository = _container.GetInstance<IMessageRepository>();
while (true)
{
_cancellationToken.ThrowIfCancellationRequested();
var message = await messageRepository.GetMessageToDeliverAsync();
if (message != null)
{
try
{
await DeliverMessageAsync(message);
}
catch (Exception ex)
{
var logEvent = new LogEvent()
{
EventType = LogEventType.Application,
LogLevel = LogLevel.Error,
Message = ex.Message,
Protocol = "SMTPD",
};
_log.LogException(logEvent, ex);
}
continue;
}
await Task.Delay(TimeSpan.FromSeconds(5), _cancellationToken);
}
}
private static LogEventInfo CreateNlogEventInfo(LogEvent logEvent)
{
var logEventInfo = new LogEventInfo();
switch (logEvent.LogLevel)
{
case LogLevel.Info:
logEventInfo.Level = NLog.LogLevel.Info;
break;
case LogLevel.Warning:
logEventInfo.Level = NLog.LogLevel.Warn;
break;
case LogLevel.Error:
logEventInfo.Level = NLog.LogLevel.Error;
break;
case LogLevel.Debug:
logEventInfo.Level = NLog.LogLevel.Debug;
break;
default:
throw new NotImplementedException(string.Format("Unsupported log level: {0}", logEvent.LogLevel));
}
logEventInfo.Message = logEvent.Message;
return logEventInfo;
}
public void LogException(LogEvent logEvent, Exception exception)
{
var logEventInfo = CreateNlogEventInfo(logEvent);
logEventInfo.Exception = exception;
Logger.Log(logEventInfo);
}
public void LogInfo(LogEvent logEvent)
{
var logEventInfo = CreateNlogEventInfo(logEvent);
Logger.Log(logEventInfo);
}
public void LogException(LogEvent logEvent, Exception exception)
{
LogEntries.Add(new Tuple<LogEvent, Exception>(logEvent, exception));
}
public void LogInfo(LogEvent logEvent)
{
LogEntries.Add(new Tuple<LogEvent, Exception>(logEvent, null));
}
public void LogException(LogEvent @event, Exception exception)
{
}
public void LogInfo(LogEvent @event)
{
}
private async Task DeliverMessageAsync(Message message)
{
var accountRepository = _container.GetInstance<IAccountRepository>();
var messageRepository = _container.GetInstance<IMessageRepository>();
var folderRepository = _container.GetInstance<IFolderRepository>();
var dnsClient = _container.GetInstance<IDnsClient>();
message.NumberOfDeliveryAttempts++;
bool isLastAttempt = message.NumberOfDeliveryAttempts >= 3;
var deliveryResults = new List<DeliveryResult>();
try
{
var remainingRecipients = new List<Recipient>(message.Recipients);
var localDelivery = new LocalDelivery(accountRepository, messageRepository, folderRepository, _log);
deliveryResults.AddRange(await localDelivery.DeliverAsync(message, remainingRecipients.Where(recipient => recipient.AccountId != 0).ToList()));
var externalDelivery = new ExternalDelivery(messageRepository, dnsClient, _log);
deliveryResults.AddRange(await externalDelivery.DeliverAsync(message, remainingRecipients.Where(recipient => recipient.AccountId == 0).ToList()));
var failedRecipients =
deliveryResults.Where(result => result.ReplyCodeSeverity == ReplyCodeSeverity.PermanentNegative ||
(isLastAttempt && result.ReplyCodeSeverity == ReplyCodeSeverity.TransientNegative));
await SubmitBounceMessageAsync(message, failedRecipients);
var deliveryCompleted =
deliveryResults.Any(result => result.ReplyCodeSeverity == ReplyCodeSeverity.TransientNegative);
if (isLastAttempt || !deliveryCompleted)
{
await messageRepository.DeleteAsync(message);
}
}
catch (Exception ex)
{
var logEvent = new LogEvent()
{
EventType = LogEventType.Application,
LogLevel = LogLevel.Error,
Protocol = "SMTPD",
};
if (isLastAttempt)
logEvent.Message = "Failed delivering message due to an error. Giving up.";
else
logEvent.Message = "Failed delivering message due to an error. Will retry later.";
_log.LogException(logEvent, ex);
if (isLastAttempt)
{
await messageRepository.DeleteAsync(message);
}
else
{
await messageRepository.UpdateAsync(message);
}
}
}