Send mail message with SSL + Authentication

Question

Hello, I'm testing a small app that needs to send emails using an SMTP server which requires SSL + Username and Password Authentication on port 465.

I've used the following code:

            string to = "[e-mail]";
            string from = "[e-mail]";
            MailMessage message = new MailMessage(from, to);
            message.Subject = "Test";
            message.Body = @"Test";

            SmtpClient client = new SmtpClient("thesmtpserver");

            client.UseDefaultCredentials = false;
            NetworkCredential cred = new NetworkCredential("[e-mail]", "mypassword");           
            client.Credentials = cred;
            client.EnableSsl = true;
            client.Port = 465;
            client.Timeout = 20000;

            try {
                client.Send(message);
            } catch (Exception e) {
                Console.WriteLine(e);
            }

I get a "Timeout Error".

Can anyone help me figure out what is wrong? If I configure Outlook Express with the same configuration it works perfectly.

Best regards

Alessandro

Answer 1

Try getting a tracelog for your application (see instructions in my signature) and see if it can tell you why the timeout is occuring.

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feroze
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My blog
Instruction on how to create a tracelog with your System.Net application

Answer 2

I can't see how the code above utilizes SSL. 

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Javaman

Answer 3

The code enables SSL by setting EnableSSL=true.

---

feroze
--
My blog
Instruction on how to create a tracelog with your System.Net application

Answer 4

Sorry for being late. I've enable tracelog and here's the result:

System.Net Information: 0 : [3440] Associating MailMessage#44419000 with Message#52697953
System.Net Verbose: 0 : [3440] SmtpClient::.ctor(host=thesmtpserver)
System.Net Information: 0 : [3440] Associating SmtpClient#22597652 with SmtpTransport#10261382
System.Net Verbose: 0 : [3440] Exiting SmtpClient::.ctor() 	-> SmtpClient#22597652
System.Net Verbose: 0 : [3440] SmtpClient#22597652::Send(MailMessage#44419000)
System.Net Information: 0 : [3440] SmtpClient#22597652::Send(DeliveryMethod=Network)
System.Net Information: 0 : [3440] Associating SmtpClient#22597652 with MailMessage#44419000
System.Net Information: 0 : [3440] Associating SmtpTransport#10261382 with SmtpConnection#59109011
System.Net Information: 0 : [3440] Associating SmtpConnection#59109011 with ServicePoint#42659827
System.Net.Sockets Verbose: 0 : [3440] Socket#40644060::Socket(InterNetwork#2)
System.Net.Sockets Verbose: 0 : [3440] Exiting Socket#40644060::Socket() 
System.Net.Sockets Verbose: 0 : [3440] Socket#40644060::Connect(218:465#-629107473)
System.Net.Sockets Verbose: 0 : [3440] Exiting Socket#40644060::Connect() 
System.Net Information: 0 : [3440] Associating SmtpConnection#59109011 with SmtpPooledStream#17043416
System.Net.Sockets Verbose: 0 : [3440] Socket#40644060::Receive()
System.Net.Sockets Verbose: 0 : [0932] Socket#40644060::Dispose()
System.Net.Sockets Error: 0 : [3440] Exception in the Socket#40644060::Receive - Operazione di blocco interrotta da una chiamata a WSACancelBlockingCall
System.Net.Sockets Verbose: 0 : [3440] Exiting Socket#40644060::Receive() 	-> 0#0
System.Net Error: 0 : [3440] Exception in the SmtpClient#22597652::Send - Impossibile leggere dati dalla connessione del trasporto: Operazione di blocco interrotta da una chiamata a WSACancelBlockingCall.
System.Net Error: 0 : [3440]    in System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   in System.Net.DelegatedStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   in System.Net.BufferedReadStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   in System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)
   in System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)
   in System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port)
   in System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port)
   in System.Net.Mail.SmtpClient.GetConnection()
   in System.Net.Mail.SmtpClient.Send(MailMessage message)
A first chance exception of type 'System.Net.Mail.SmtpException' occurred in System.dll
System.Net Verbose: 0 : [3440] Exiting SmtpClient#22597652::Send() 
System.Net.Mail.SmtpException: Timeout dell'operazione.
   in System.Net.Mail.SmtpClient.Send(MailMessage message)
   in GuiTest.Program.Main() in C:\GuiTest\Program.cs:riga 49

Answer 5

The trace indicates the three-way handshake failed.  You sent a packet to nowhere.

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Javaman

Answer 6

From the trace it looks like the client connected to the server, but the server did not respond.

Can you try the same code against a different SMTP server?

---

feroze
--
My blog
Instruction on how to create a tracelog with your System.Net application

Answer 7

Agreed that's what happened the server didn't respond.

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Javaman

Answer 8

I do not understand why it works perfectly if I use the following deprecated code:

System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserver"] = "thesmtpserver";
mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"] = 2;
mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"] = 465;
mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpusessl"] = "true";
mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"] = 1;
mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendusername"] = "[e-mail]";
mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"] = "mypassword";
mail.To = "[e-mail]";
mail.From = "[e-mail]";
mail.Subject = "Test";
mail.Body = "Test";
mail.BodyFormat = System.Web.Mail.MailFormat.Html;            
System.Web.Mail.SmtpMail.SmtpServer = "thesmtpserver";
System.Web.Mail.SmtpMail.Send(mail); 

Best regards

Alessandro

Answer 9

Can you get a tracelog of this session, just as  you did before?

---

feroze
--
My blog
Instruction on how to create a tracelog with your System.Net application