sending mail fail through app in windows 2008 server

[sending mail fail through app in windows]

while sending the mails through .net windows application 2.0 from windows
2008 server (application is running in windows 2008) which is raised the
following error.
System.Net.WebException: Unable to connect to the remote server

{System.Net.Mail.SmtpException: Failure sending mail. --->
System.Net.WebException: Unable to connect to the remote server --->
System.Net.Sockets.SocketException: No connection could be made because the
target machine actively refused it 10.200.206.80:25
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)

but same application is working in some different machines in xp or win 2003.

[Lawrence Garvin [MVP]]

"sending mail fail through app in windows" <sending mail fail through app in

Post by sending mail fail through app in windows
while sending the mails through .net windows application 2.0 from windows
2008 server (application is running in windows 2008) which is raised the
following error.
System.Net.WebException: Unable to connect to the remote server

And this has to do with WSUS . . . How?

Post by sending mail fail through app in windows
System.Net.Sockets.SocketException: No connection could be made because the
target machine actively refused it 10.200.206.80:25

Whatever it is... it's a permissions error. The email server is DENYING the
connection.

Post by sending mail fail through app in windows
but same application is working in some different machines in xp or win 2003.

Then you need to do for this machine what you've already done for those
other machines.