通过雅虎发送邮件错误

从雅虎发送邮件错误。我尝试过端口25,995,465,587!我现在别无选择了。如果有人能告诉我是什么问题，我将不胜感激。难道雅虎现在没有SMTP吗? !我在哪里读到这是一项付费服务之类的?这是正确的，是不是因为这一点，我不能通过服务器!我可以成功地从我的gmail帐户发送电子邮件，其中收件人和发件人是相同的，我也从gmail发送邮件到雅虎，但反向不工作!

 MailMessage mail = new MailMessage();
 mail.From = new MailAddress(something@yahoo.co.in);
 //***Enter recievers Email here (TVC)
 mail.To.Add(new MailAddress("something@gmail.com"));
 mail.Subject = "This is some text";
 mail.Body = "This is the body";
 SmtpClient client = new SmtpClient("plus.smtp.mail.yahoo.com",995);
 client.Credentials = new System.Net.NetworkCredential("somehting@yahoo.co.in", "pass");
 client.EnableSsl = true;
 client.Send(mail);
 MessageBox.Show("Mail Sent Successfully!", "Success", MessageBoxButtons.OK);

得到以下异常

System.Net.Mail.SmtpException was unhandled
Message=Failure sending mail.
Source=System
StackTrace:
   at System.Net.Mail.SmtpClient.Send(MailMessage message)
   at WindowsFormsApplication1.frmSelfAssessment.mailToTVC()
   at WindowsFormsApplication1.frmEnterEmail.button1_Click(Object sender, EventArgs e)
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.RunDialog(Form form)
   at System.Windows.Forms.Form.ShowDialog(IWin32Window owner)
   at System.Windows.Forms.Form.ShowDialog()
   at WindowsFormsApplication1.frmSelfAssessment.btnSubmit_Click(Object sender, EventArgs e)
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.UserControl.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at WindowsFormsApplication1.Program.Main()
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()
   InnerException: System.IO.IOException
   Message=Unable to read data from the transport connection: net_io_connectionclosed.
   Source=System
   StackTrace:
        at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine)
        at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)
        at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)
        at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
        at System.Net.Mail.SmtpTransport.GetConnection(ServicePoint servicePoint)
        at System.Net.Mail.SmtpClient.GetConnection()
        at System.Net.Mail.SmtpClient.Send(MailMessage message)
   InnerException:

在使用try catch块之后这就是我得到的

System.Net.Mail.SmtpException: Failure sending mail. ---> System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed.
at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine)
at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)
at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)
at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
at System.Net.Mail.SmtpTransport.GetConnection(ServicePoint servicePoint)
at System.Net.Mail.SmtpClient.GetConnection()
at System.Net.Mail.SmtpClient.Send(MailMessage message)
--- End of inner exception stack trace ---
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at WindowsFormsApplication1.frmSelfAssessment.mailToTVC()