问题是有关在ASP.NET中发送电子邮件

Question

protected void SendEmail(object sender, EventArgs e)
    {
        SmtpClient smtpClient = new SmtpClient();
        MailMessage message = new MailMessage();
        try
        {
            MailAddress fromAddress = new MailAddress("fromemail", "From Me");
            MailAddress toAddress = new MailAddress("toemail", "To You");
            message.From = fromAddress;
            message.To.Add(toAddress);
            message.Subject = "Testing!";
            message.Body = "This is the body of a sample message";
            smtpClient.Host = "smtp.host.com";
            smtpClient.Credentials = new System.Net.NetworkCredential("username", "password");
            smtpClient.EnableSsl = true;
            smtpClient.Port = 587;
            smtpClient.Send(message);
            statusLabel.Text = "Email sent.";
        }
        catch (Exception ex)
        {
            statusLabel.Text = "Coudn't send the message!\n"+ex.Message;
        }
    }

The error is

"Failure sending mail."

I can not send any. What is the problem?

innerexception is

System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 74.125.39.109:587 at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.InternalConnect(EndPoint remoteEP) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception) --- End of inner exception stack trace --- at System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6, Int32 timeout) at System.Net.PooledStream.Activate(Object owningObject, Boolean async, Int32 timeout, GeneralAsy ncDelegate asyncCallback) at System.Net.PooledStream.Activate(Object owningObject, GeneralAsyncDelegate asyncCallback) at System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout) at System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port) at System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port) at System.Net.Mail.SmtpClient.GetConnection() at System.Net.Mail.SmtpClient.Send(MailMessage message)

Answer 1

For an SmtpException , you always have to examine the inner exception through the Exception.InnerException property. Always.

Answer 2

Remove the try/catch and see what happens :-)

You can test locally first:

<mailSettings>
    <smtp deliveryMethod='SpecifiedPickupDirectory'>
        <specifiedPickupDirectory pickupDirectoryLocation="c:\maildrop" />
    </smtp>
</mailSettings>

More details:

http://weblogs.asp.net/gunnarpeipman/archive/2010/05/27/asp-net-using-pickup-directory-for-outgoing-e-mails.aspx

Answer 3

From the inner exception: 74.125.39.109:587 cannot be reached.

Make sure:

1. 74.125.39.109:587 actually has a SMTP server running
2. From the server running the code, make sure you can connect to that IP:Port (there isn't a firewall or virus scanner blocking the outgoing smtp connection attempt).

One way to test, is from that same server, open a telnet connection to 74.125.39.109:587.

Answer 4

u have use 587 as the port....this is similar to gmail's smtp service port number....if ur using gmail smtp service...try use this...

host: smtp.gmail.com port: 587

in network ceredentials give ur valid gmail username and its password...

also check ur internet connectivity

Answer 5

Try taking out all the smtp server settings and place the mailSettings in your app/web.config

Sometimes mail servers will not allow mail relaying. In this case, you will need to set up a virtual smtp server.

Relaying in IIS 6

If you are using windows server 2008, you will need to install the IIS 6 management console to configure relaying.

Answer 6

Default SMPT port is 25. You are using 587, could this be the problem. Or is there a reason for using port?

Answer 7

I remember i face similar problem the solution i find is:

before:

smtpClient.Send(message);

Put this line:

ServicePointManager.ServerCertificateValidationCallback = delegate(object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; };

BTW:

the port should be: smtp.Port = 25;