/// <summary>
/// Queues the email for relaying.
/// </summary>
private async Task <SmtpServerTransactionAsyncResult> QueueForRelayingAsync()
{
// The email is for relaying.
Guid messageID = Guid.NewGuid();
// Look for any MTA control headers.
MessageHeaderCollection headers = MessageManager.GetMessageHeaders(Data);
// Will not be null if the SendGroupID header was present.
MessageHeader ipGroupHeader = headers.SingleOrDefault(m => m.Name.Equals(MessageHeaderNames.SendGroupID, StringComparison.OrdinalIgnoreCase));
// Parameter will hold the MtaIPGroup that will be used to relay this message.
VirtualMtaGroup mtaGroup = null;
int ipGroupID = 0;
if (ipGroupHeader != null)
{
if (int.TryParse(ipGroupHeader.Value, out ipGroupID))
{
mtaGroup = VirtualMtaManager.GetVirtualMtaGroup(ipGroupID);
}
}
#region Look for a send id, if one doesn't exist create it.
MessageHeader sendIdHeader = headers.SingleOrDefault(h => h.Name.Equals(MessageHeaderNames.SendID, StringComparison.OrdinalIgnoreCase));
int internalSendId = -1;
if (sendIdHeader != null)
{
Send sndID = await SendManager.Instance.GetSendAsync(sendIdHeader.Value);
if (sndID.SendStatus == SendStatus.Discard)
{
return(SmtpServerTransactionAsyncResult.FailedSendDiscarding);
}
internalSendId = sndID.InternalID;
}
else
{
Send sndID = await SendManager.Instance.GetDefaultInternalSendIdAsync();
if (sndID.SendStatus == SendStatus.Discard)
{
return(SmtpServerTransactionAsyncResult.FailedSendDiscarding);
}
internalSendId = sndID.InternalID;
}
#endregion
#region Generate Return Path
string returnPath = string.Empty;
// Can only return path to messages with one rcpt to
if (RcptTo.Count == 1)
{
// Need to check to see if the message contains a return path overide domain.
MessageHeader returnPathDomainOverrideHeader = headers.SingleOrDefault(h => h.Name.Equals(MessageHeaderNames.ReturnPathDomain, StringComparison.OrdinalIgnoreCase));
if (returnPathDomainOverrideHeader != null &&
MtaParameters.LocalDomains.Count(d => d.Hostname.Equals(returnPathDomainOverrideHeader.Value, StringComparison.OrdinalIgnoreCase)) > 0)
{
// The message contained a local domain in the returnpathdomain
// header so use it instead of the default.
returnPath = ReturnPathManager.GenerateReturnPath(RcptTo[0], internalSendId, returnPathDomainOverrideHeader.Value);
}
else
{
// The message didn't specify a return path overide or it didn't
// contain a localdomain so use the default.
returnPath = ReturnPathManager.GenerateReturnPath(RcptTo[0], internalSendId);
}
// Insert the return path header.
Data = MessageManager.AddHeader(Data, new MessageHeader("Return-Path", "<" + returnPath + ">"));
}
else
{
// multiple rcpt's so can't have unique return paths, use generic mail from.
returnPath = MailFrom;
}
#endregion
#region Generate a message ID header
string msgIDHeaderVal = "<" + messageID.ToString("N") + MailFrom.Substring(MailFrom.LastIndexOf("@")) + ">";
// If there is already a message header, remove it and add our own. required for feedback loop processing.
if (headers.Count(h => h.Name.Equals("Message-ID", StringComparison.OrdinalIgnoreCase)) > 0)
{
Data = MessageManager.RemoveHeader(Data, "Message-ID");
}
// Add the new message-id header.
Data = MessageManager.AddHeader(Data, new MessageHeader("Message-ID", msgIDHeaderVal));
#endregion
#region Get message priority
var msgPriority = RabbitMqPriority.Low;
var priorityHeader = headers.GetFirstOrDefault(MessageHeaderNames.Priority);
if (priorityHeader != null)
{
var outVal = 0;
if (int.TryParse(priorityHeader.Value, out outVal))
{
if (outVal >= 0)
{
msgPriority = outVal < 3 ? (RabbitMqPriority)(byte)outVal
: RabbitMqPriority.High;
}
}
}
#endregion
// Remove any control headers.
headers = new MessageHeaderCollection(headers.Where(h => h.Name.StartsWith(MessageHeaderNames.HeaderNamePrefix, StringComparison.OrdinalIgnoreCase)));
foreach (MessageHeader header in headers)
{
Data = MessageManager.RemoveHeader(Data, header.Name);
}
// If the MTA group doesn't exist or it's not got any IPs, use the default.
if (mtaGroup == null ||
mtaGroup.VirtualMtaCollection.Count == 0)
{
ipGroupID = VirtualMtaManager.GetDefaultVirtualMtaGroup().ID;
}
// Attempt to Enqueue the Email for Relaying.
var enqueued = await QueueManager.Instance.Enqueue(messageID, ipGroupID, internalSendId, returnPath, RcptTo.ToArray(), Data, msgPriority);
return(enqueued ? SmtpServerTransactionAsyncResult.SuccessMessageQueued
: SmtpServerTransactionAsyncResult.FailedToEnqueue);
}
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;
}
}
}
}
private async Task <bool> 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(false);
}
if (await Data.MtaTransaction.HasBeenHandledAsync(msg.ID))
{
msg.IsHandled = true;
return(true);
}
// Get the send that this message belongs to so that we can check the send state.
Send 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(false);
// 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(false);
// 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(false);
}
bool result;
// 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);
result = false;
}
else
{
MailAddress mailAddress = new MailAddress(msg.RcptTo[0]);
MailAddress mailFrom = new MailAddress(msg.MailFrom);
MXRecord[] mXRecords = DNSManager.GetMXRecords(mailAddress.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);
result = false;
}
else if (IsMxBlacklisted(mXRecords))
{
await MtaMessageHelper.HandleDeliveryFailAsync(msg, "550 Domain blacklisted.", null, mXRecords[0]);
result = false;
}
else
{
// The IP group that will be used to send the queued message.
VirtualMtaGroup virtualMtaGroup = VirtualMtaManager.GetVirtualMtaGroup(msg.VirtualMTAGroupID);
VirtualMTA sndIpAddress = virtualMtaGroup.GetVirtualMtasForSending(mXRecords[0]);
SmtpOutboundClientDequeueResponse dequeueResponse = await SmtpClientPool.Instance.DequeueAsync(sndIpAddress, mXRecords);
switch (dequeueResponse.DequeueResult)
{
case SmtpOutboundClientDequeueAsyncResult.Success:
case SmtpOutboundClientDequeueAsyncResult.NoMxRecords:
case SmtpOutboundClientDequeueAsyncResult.FailedToAddToSmtpClientQueue:
case SmtpOutboundClientDequeueAsyncResult.Unknown:
break; // Don't need to do anything for these results.
case SmtpOutboundClientDequeueAsyncResult.FailedToConnect:
await MtaMessageHelper.HandleFailedToConnectAsync(msg, sndIpAddress, mXRecords[0]);
break;
case SmtpOutboundClientDequeueAsyncResult.ServiceUnavalible:
await MtaMessageHelper.HandleServiceUnavailableAsync(msg, sndIpAddress);
break;
case SmtpOutboundClientDequeueAsyncResult.Throttled:
await MtaMessageHelper.HandleDeliveryThrottleAsync(msg, sndIpAddress, mXRecords[0]);
break;
case SmtpOutboundClientDequeueAsyncResult.FailedMaxConnections:
msg.AttemptSendAfterUtc = DateTime.UtcNow.AddSeconds(2);
await RabbitMqOutboundQueueManager.Enqueue(msg);
break;
}
SmtpOutboundClient smtpClient = dequeueResponse.SmtpOutboundClient;
// If no client was dequeued then we can't currently send.
// This is most likely a max connection issue. Return false but don't
// log any deferal or throttle.
if (smtpClient == null)
{
result = false;
}
else
{
try
{
Action <string> failedCallback = delegate(string smtpResponse)
{
// If smtpRespose starts with 5 then perm error should cause fail
if (smtpResponse.StartsWith("5"))
{
MtaMessageHelper.HandleDeliveryFailAsync(msg, smtpResponse, sndIpAddress, smtpClient.MXRecord).Wait();
}
else
{
// If the MX is actively denying use service access, SMTP code 421 then we should inform
// the ServiceNotAvailableManager manager so it limits our attepts to this MX to 1/minute.
if (smtpResponse.StartsWith("421"))
{
ServiceNotAvailableManager.Add(smtpClient.SmtpStream.LocalAddress.ToString(), smtpClient.MXRecord.Host, DateTime.UtcNow);
MtaMessageHelper.HandleDeliveryDeferral(msg, smtpResponse, sndIpAddress, smtpClient.MXRecord, true);
}
else
{
// Otherwise message is deferred
MtaMessageHelper.HandleDeliveryDeferral(msg, smtpResponse, sndIpAddress, smtpClient.MXRecord, false);
}
}
throw new SmtpTransactionFailedException();
};
// Run each SMTP command after the last.
await smtpClient.ExecHeloOrRsetAsync(failedCallback);
await smtpClient.ExecMailFromAsync(mailFrom, failedCallback);
await smtpClient.ExecRcptToAsync(mailAddress, failedCallback);
await smtpClient.ExecDataAsync(msg.Message, failedCallback, async (response) => {
await MtaMessageHelper.HandleDeliverySuccessAsync(msg, sndIpAddress, smtpClient.MXRecord, response);
});
SmtpClientPool.Instance.Enqueue(smtpClient);
result = true;
}
catch (SmtpTransactionFailedException)
{
// Exception is thrown to exit transaction, logging of deferrals/failers already handled.
result = false;
}
catch (Exception ex)
{
Logging.Error("MessageSender error.", ex);
if (msg != null)
{
MtaMessageHelper.HandleDeliveryDeferral(msg, "Connection was established but ended abruptly.", sndIpAddress, smtpClient.MXRecord, false);
}
result = false;
}
finally
{
if (smtpClient != null)
{
smtpClient.IsActive = false;
smtpClient.LastActive = DateTime.UtcNow;
}
}
}
}
}
return(result);
}
