private async Task SendMessageAsync(MtaQueuedMessage msg)
{
// Check that the message next attempt after has passed.
if (msg.AttemptSendAfterUtc > DateTime.UtcNow)
{
await RabbitMqOutboundQueueManager.Enqueue(msg);
await Task.Delay(50); // To prevent a tight loop within a Task thread we should sleep here.
return;
}
if (await Data.MtaTransaction.HasBeenHandledAsync(msg.ID))
{
msg.IsHandled = true;
return;
}
// Get the send that this message belongs to so that we can check the send state.
var snd = await SendManager.Instance.GetSendAsync(msg.InternalSendID);
switch (snd.SendStatus)
{
// The send is being discarded so we should discard the message.
case SendStatus.Discard:
await MtaMessageHelper.HandleMessageDiscardAsync(msg);
return;
// The send is paused, the handle pause state will delay, without deferring, the message for a while so we can move on to other messages.
case SendStatus.Paused:
await MtaMessageHelper.HandleSendPaused(msg);
return;
// Send is active so we don't need to do anything.
case SendStatus.Active:
break;
// Unknown send state, requeue the message and log error. Cannot send!
default:
msg.AttemptSendAfterUtc = DateTime.UtcNow.AddMinutes(1);
await RabbitMqOutboundQueueManager.Enqueue(msg);
Logging.Error("Failed to send message. Unknown SendStatus[" + snd.SendStatus + "]!");
return;
}
// Check the message hasn't timed out. If it has don't attempt to send it.
// Need to do this here as there may be a massive backlog on the server
// causing messages to be waiting for ages after there AttemptSendAfter
// before picking up. The MAX_TIME_IN_QUEUE should always be enforced.
if (msg.AttemptSendAfterUtc - msg.QueuedTimestampUtc > new TimeSpan(0, MtaParameters.MtaMaxTimeInQueue, 0))
{
await MtaMessageHelper.HandleDeliveryFailAsync(msg, MtaParameters.TIMED_OUT_IN_QUEUE_MESSAGE, null, null);
}
else
{
MailAddress rcptTo = new MailAddress(msg.RcptTo[0]);
MailAddress mailFrom = new MailAddress(msg.MailFrom);
MXRecord[] mXRecords = DNSManager.GetMXRecords(rcptTo.Host);
// If mxs is null then there are no MX records.
if (mXRecords == null || mXRecords.Length < 1)
{
await MtaMessageHelper.HandleDeliveryFailAsync(msg, "550 Domain Not Found.", null, null);
}
else if (IsMxBlacklisted(mXRecords))
{
await MtaMessageHelper.HandleDeliveryFailAsync(msg, "550 Domain blacklisted.", null, mXRecords[0]);
}
else
{
var vMtaGroup = VirtualMtaManager.GetVirtualMtaGroup(msg.VirtualMTAGroupID);
var sendResult = await MantaSmtpClientPoolCollection.Instance.SendAsync(mailFrom, rcptTo, vMtaGroup, mXRecords, msg.Message);
switch (sendResult.MantaOutboundClientResult)
{
case MantaOutboundClientResult.FailedToConnect:
await MtaMessageHelper.HandleFailedToConnectAsync(msg, sendResult.VirtualMTA, sendResult.MXRecord);
break;
case MantaOutboundClientResult.MaxConnections:
await RabbitMqOutboundQueueManager.Enqueue(msg);
break;
case MantaOutboundClientResult.MaxMessages:
await MtaMessageHelper.HandleDeliveryThrottleAsync(msg, sendResult.VirtualMTA, sendResult.MXRecord);
break;
case MantaOutboundClientResult.RejectedByRemoteServer:
if (string.IsNullOrWhiteSpace(sendResult.Message))
{
Logging.Error("RejectedByRemoteServer but no message!");
await MtaMessageHelper.HandleDeliveryDeferralAsync(msg, sendResult.Message, sendResult.VirtualMTA, sendResult.MXRecord);
}
if (sendResult.Message[0] == '4')
{
await MtaMessageHelper.HandleDeliveryDeferralAsync(msg, sendResult.Message, sendResult.VirtualMTA, sendResult.MXRecord);
}
else
{
await MtaMessageHelper.HandleDeliveryFailAsync(msg, sendResult.Message, sendResult.VirtualMTA, sendResult.MXRecord);
}
break;
case MantaOutboundClientResult.ServiceNotAvalible:
await MtaMessageHelper.HandleServiceUnavailableAsync(msg, sendResult.VirtualMTA);
break;
case MantaOutboundClientResult.Success:
await MtaMessageHelper.HandleDeliverySuccessAsync(msg, sendResult.VirtualMTA, sendResult.MXRecord, sendResult.Message);
break;
default:
// Something weird happening with this message, get it out of the way for a bit.
msg.AttemptSendAfterUtc = DateTime.UtcNow.AddMinutes(5);
await RabbitMqOutboundQueueManager.Enqueue(msg);
break;
}
}
}
}
