public async Task LookupWithFallback_FailedAll()
{
var mockMailReference = new MockMailReference(
"mock-1",
"*****@*****.**",
new[] { "*****@*****.**" }.ToImmutableList(),
true,
"Some text",
_queue);
_queue.References.Add(mockMailReference);
_dns.AddMx("example.com", "first.example.com", 10);
_dns.AddIp("first.example.com", IPAddress.Parse("10.0.0.1"));
Task executeTask = Task.Run(
() => _transfer.SendMailsToDomain("example.com", new[] { mockMailReference }, CancellationToken.None));
MockTcpConnectionProvider.MockTcpClient client = await GetClientFor(IPAddress.Parse("10.0.0.1"));
await WriteToAsync(
client.HalfStream,
@"554 Failed
554 Failed
");
await executeTask;
Assert.Equal(1, _queue.References.Count);
Assert.Equal(0, _queue.DeletedReferences.Count);
SmtpFailureData failure = _failures.GetFailure("mock-1", false);
Assert.NotNull(failure);
Assert.Equal(1, failure.Retries);
Assert.InRange(failure.FirstFailure, DateTimeOffset.UtcNow - TimeSpan.FromSeconds(1), DateTime.UtcNow);
}
public SmtpFailureData ShouldAttemptRedelivery(IMailReference mail)
{
SmtpFailureData failure = _failures.GetFailure(mail.Id, true);
if (failure.Retries + 1 >= s_retryDelays.Length)
{
return(null);
}
return(failure);
}
public void ShouldAttemptRetryAfterSingleFailure()
{
Assert.NotNull(
_transfer.ShouldAttemptRedelivery(
new MockMailReference(
"mock-1",
"*****@*****.**",
new[] { "*****@*****.**" }.ToImmutableList(),
true,
_queue)));
SmtpFailureData failure = _failures.GetFailure("mock-1", false);
Assert.NotNull(failure);
Assert.InRange(failure.FirstFailure, DateTimeOffset.UtcNow - TimeSpan.FromSeconds(1), DateTime.UtcNow);
}
public SmtpFailureData GetFailure(string mailId, bool createIfMissing)
{
if (!CurrentFailures.TryGetValue(mailId, out SmtpFailureData failure))
{
if (createIfMissing)
{
failure = new SmtpFailureData(mailId)
{
FirstFailure = DateTimeOffset.UtcNow, Retries = 0
};
CurrentFailures.Add(mailId, failure);
}
}
return(failure);
}
public SmtpFailureData GetFailure(string mailId, bool createIfMissing)
{
if (!_failures.Value.TryGetValue(mailId, out SmtpFailureData failure))
{
if (!createIfMissing)
{
return(null);
}
failure = new SmtpFailureData(mailId)
{
FirstFailure = DateTimeOffset.UtcNow, Retries = 0
};
_failures.Value.Add(mailId, failure);
}
return(failure);
}
public bool IsReadyToSend(IMailReference mail)
{
SmtpFailureData failure = _failures.GetFailure(mail.Id, false);
if (failure == null)
{
return(true);
}
TimeSpan currentLag = DateTimeOffset.UtcNow - failure.FirstFailure;
if (currentLag < CalculateNextRetryInterval(failure.Retries))
{
return(false);
}
return(true);
}
private async Task HandleFailedMailsAsync(IReadOnlyList <IMailReference> unsent)
{
foreach (IMailReference mail in unsent)
{
SmtpFailureData retryData = ShouldAttemptRedelivery(mail);
if (retryData == null)
{
// We're giving up, forget about it
_failures.RemoveFailure(mail.Id);
await HandleRejectedMailAsync(mail);
await _queue.DeleteAsync(mail);
}
else
{
retryData.Retries++;
}
}
}