// connect and log in to an SSH server
var ssh = new Rebex.Net.Ssh();
ssh.Connect(hostname);
ssh.Login(username, password);

// create port forwarding rule
// to accept connections at localhost:44000
// and tunnel then over SSH session through the SSH server
// to the specified IMAP server
SshTunnel tunnel = ssh.StartOutgoingTunnel(
    "localhost", 44000,      // client-side source address
    imapHostname, imapPort); // server-side target address

// establish a connection to the remote IMAP server
// by connecting to localhost:44000
// (we are using Rebex IMAP here, but third-party
// application should work as well)
var imap = new Rebex.Net.Imap();
imap.Connect("localhost", 44000);
imap.Login(imapUsername, imapPassword);

// use Imap object to download some messages, etc.
// ...

// finish work with IMAP
imap.Disconnect();

// stop port forwarding
tunnel.Close();

// close SSH connection
ssh.Disconnect();

// connect and log in to an SSH server
var ssh = new Rebex.Net.Ssh();
ssh.Connect(hostname);
ssh.Login(username, password);

// create port forwarding rule
// to accept connections on port 55000 at the server
// and tunnel them over SSH session through the SSH client
// to port 44000 at the client
var tunnel = ssh.StartIncomingTunnel(
    "localhost", 55000,  // server-side source address/port
    "localhost", 44000); // client-side target address/port

// listen for incoming connections at local port 44000
var listener = new TcpListener(IPAddress.Any, 44000);
listener.Start();

// accept connections tunneled from the server
while (acceptConnections)
{
    TcpClient client = listener.AcceptTcpClient();

    // do something
    // ...
}

// use telnet command to connect through the incoming tunnel
// (listening at localhost:55000) to the target endpoint
var scripting = ssh.StartScripting("telnet localhost 55000");

// wait to initialize telnet
scripting.WaitFor("Escape character is");
scripting.WaitFor(ScriptEvent.Line);

// send something
scripting.SendCommand("Hello there");

// read response
string response = scripting.ReadLine();

// establish the shared SSH connection
var session = new SshSession();
session.Connect(hostname);
session.Authenticate(username, password);

// use SSH session as proxy to establish another SSH connection
var ssh = new Rebex.Net.Ssh();
ssh.SetSocketFactory(session.ToSocketFactory());
ssh.Connect(sftpHostname);
ssh.Login(sftpUsername, sftpPassword);
// use Ssh object to execute commands, etc.

// use SSH session as proxy to establish IMAP connection
var imap = new Rebex.Net.Imap();
imap.SetSocketFactory(session.ToSocketFactory());
imap.Connect(imapHostname);
imap.Login(imapUsername, imapPassword);
// use Imap object to download mail messages, etc.

// use it with any Rebex library in the same way
// (Ssh, Sftp, Ftp, Scp, Smtp, Imap, Pop3, Telnet, WebClient objects)