System.Net.Mail Error: Unable to read data from the transport connection: net_io_connectionclosed

[nate.strules]

I've looked everywhere for an answer to this, but only a few people
seem to have encountered it.

The code is straightforward:

MailMessage mail = new MailMessage(from, to, subject, body);
SmtpClient client = new SmtpClient("localhost");
client.Send (mail);

The code works fine on my development machine (XP Pro). When moved to
staging (2003 Server), I get the "connection closed" error. I've
confirmed the following:

-- "localhost" resolves to 127.0.0.1 (also tried using the loopback
address with the same error)
-- SMTP service is running on port 25
-- service is configured to relay mail
-- another app (Community Server) is using the service to send email
without any problems.

I'm at wit's end

TIA

 

[nate.strules]

As usual, this problem was resolved out not long after posting this
message. The problem was how the SMTP service was set up.
Specifically, the service has been bound to a specific IP address (not
the webserver's; see the "IP Address" dropdown in the "General" tab).
Once this was set to "(All Unassigned)". Everything worked fine.
Hopefully this message will save someone the hours of aggravation I
endured.

 

[narayanak]

As usual, this problem was resolved out not long after posting this
message. The problem was how the SMTP service was set up.
Specifically, the service has been bound to a specific IP address (not
the webserver's; see the "IP Address" dropdown in the "General" tab).
Once this was set to "(All Unassigned)". Everything worked fine.
Hopefully this message will save someone the hours of aggravation I
endured.

(e-mail address removed) wrote:
> I've looked everywhere for an answer to this, but only a few people
> seem to have encountered it.
>
> The code is straightforward:
>
> MailMessage mail = new MailMessage(from, to, subject, body);
> SmtpClient client = new SmtpClient("localhost");
> client.Send (mail);
>
> The code works fine on my development machine (XP Pro). When moved to
> staging (2003 Server), I get the "connection closed" error. I've
> confirmed the following:
>
> -- "localhost" resolves to 127.0.0.1 (also tried using the loopback
> address with the same error)
> -- SMTP service is running on port 25
> -- service is configured to relay mail
> -- another app (Community Server) is using the service to send email
> without any problems.
>
> I'm at wit's end
>
> TIA

Hi,
As you said I have configured the SMTP and there is no error coming to me but the email is not going to specific address. Instead it is stored as .EML file in "C:\Inetpub\mailroot\Queue" folder.
This is the code
Dim mailServerName As String = "110.119.190.238"
Try
Dim message As New MailMessage(from, too, subject, Body)
message.IsBodyHtml = True
Dim mailClient As New SmtpClient()
mailClient.Host = mailServerName
mailClient.Port = 25
mailClient.UseDefaultCredentials = True
mailClient.DeliveryMethod = SmtpDeliveryMethod.Network
Dim attachmentPath As String = Server.MapPath("Report.pdf")
Dim attach As New Attachment(attachmentPath)
message.Attachments.Add(attach)
mailClient.Send(message)
Catch Ex As SmtpException
Throw New ApplicationException("SmtpException has oCCured: " + Ex.Message)
Catch Ex As Exception
Throw Ex
End Try

Here I am specifying the "DeliveryMethod = SmtpDeliveryMethod.Network" also. Instead of that also it is not sending the mail. If I remove also it is storing .EML file in the above mentioned folder.

Please help me out.
thanks
Narayana

 

[jzhou07]

Problem solved, but why?

Thanks for the sharing this with us, it does save me a lot of time. But I am wondering why it solves the problem? I am calling the smtp from one of my web service which sits on the machine that specified on the drop down list, why shall I change it to All Unassigned?

Jason

As usual, this problem was resolved out not long after posting this
message. The problem was how the SMTP service was set up.
Specifically, the service has been bound to a specific IP address (not
the webserver's; see the "IP Address" dropdown in the "General" tab).
Once this was set to "(All Unassigned)". Everything worked fine.
Hopefully this message will save someone the hours of aggravation I
endured.

(e-mail address removed) wrote:
> I've looked everywhere for an answer to this, but only a few people
> seem to have encountered it.
>
> The code is straightforward:
>
> MailMessage mail = new MailMessage(from, to, subject, body);
> SmtpClient client = new SmtpClient("localhost");
> client.Send (mail);
>
> The code works fine on my development machine (XP Pro). When moved to
> staging (2003 Server), I get the "connection closed" error. I've
> confirmed the following:
>
> -- "localhost" resolves to 127.0.0.1 (also tried using the loopback
> address with the same error)
> -- SMTP service is running on port 25
> -- service is configured to relay mail
> -- another app (Community Server) is using the service to send email
> without any problems.
>
> I'm at wit's end
>
> TIA

 

[karlitros]

You don't have to set the IP address box to all unassigned, you can simply use the IP address that's specified as it stands. That's what I did, anyway.

And yes, I registered just to answer this question!