I’m making a web sites using asp.net in my local server, why can I send email from my local server?

Server Error in ‘/membership’ Application.
No connection could be made because the target machine actively refused it 127.0.0.1:25
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: No connection could be made because the target machine actively refused it 127.0.0.1:25

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 (0x274d): No connection could be made because the target machine actively refused it 127.0.0.1:25]
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
System.Web.UI.WebControls.LoginUtil.SendPasswordMail(String email, String userName, String password, MailDefinition mailDefinition, String defaultSubject, String defaultBody, OnSendingMailDelegate onSendingMailDelegate, OnSendMailErrorDelegate onSendMailErrorDelegate, Control owner) +367
System.Web.UI.WebControls.PasswordRecovery.AttemptSendPasswordQuestionView() +522
System.Web.UI.WebControls.PasswordRecovery.AttemptSendPassword() +69
System.Web.UI.WebControls.PasswordRecovery.OnBubbleEvent(Object source, EventArgs e) +103
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +118
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +166
System.Web.UI.WebControls.Button.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

Version Information: Microsoft .NET Framework Version:2.0.50727.3074; ASP.NET Version:2.0.50727.3074
please give more details answer 1, show me how to do that…..