Error: A connection attempt failed

 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 75.125.56.238:25
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
 
Exception Details: 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 75.125.56.238:25
 
Source Error:
 
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
 
Stack Trace:
 
[SocketException (0x274c): 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 75.125.56.238:25]
   System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) +239
   System.Net.Sockets.Socket.InternalConnect(EndPoint remoteEP) +35
   System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception) +224
 
[WebException: Unable to connect to the remote server]
   System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6, Int32 timeout) +5421675
   System.Net.PooledStream.Activate(Object owningObject, Boolean async, Int32 timeout, GeneralAsyncDelegate asyncCallback) +202
   System.Net.PooledStream.Activate(Object owningObject, GeneralAsyncDelegate asyncCallback) +21
   System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout) +332
   System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port) +160
   System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port) +159
   System.Net.Mail.SmtpClient.GetConnection() +35
   System.Net.Mail.SmtpClient.Send(MailMessage message) +1213
 
[SmtpException: Failure sending mail.]
   System.Net.Mail.SmtpClient.Send(MailMessage message) +1531
   CommonMethods.sendMail(MailMessage mail) +246
   solutionRoom.sendMail(String ProjectID) +610
   solutionRoom.btnSubmitSolution_Click(Object sender, ImageClickEventArgs e) +97
   System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +108
   System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) +118
   System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565
                                              

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