An attempt was made to access a socket in a way forbidden by its access permissions ... SMTP

Hi,
I try to send email with SMTP client... i riceve this error
 
[SocketException (0x271d): An attempt was made to access a socket in a way forbidden by its access permissions 10.113.34.36:25] System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) +269 System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception) +649

My server is Windows Server 2008 , with IIS 7.5 .
I also try to put off firewall. If install e client o email like thunderbird or outlook .. it work!!

Help me!!!
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