(C++) POP3 over Multiple Hop SSH

Demonstrates how to read POP3 email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => POP3Server

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#include <CkSsh.h>
#include <CkMailMan.h>
#include <CkEmail.h>

void ChilkatSample(void)
    {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkSsh ssh1;

    // Connect directly to the 1st SSH server.
    bool success = ssh1.Connect("serverssh1.com",22);
    if (success != true) {
        std::cout << ssh1.lastErrorText() << "\r\n";
        return;
    }

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("ssh1Login","ssh1Password");
    if (success != true) {
        std::cout << ssh1.lastErrorText() << "\r\n";
        return;
    }

    // Connect through the 1st SSH connection to reach a 2nd SSH server.
    // Note: Any number of SSH connections may be simultaneously tunneled through a single
    // existing SSH connection.
    CkSsh ssh2;
    success = ssh2.ConnectThroughSsh(ssh1,"serverssh2.com",22);
    if (success != true) {
        std::cout << ssh2.lastErrorText() << "\r\n";
        return;
    }

    // Authenticate with ssh2...
    success = ssh2.AuthenticatePw("ssh2Login","ssh2Password");
    if (success != true) {
        std::cout << ssh2.lastErrorText() << "\r\n";
        return;
    }

    CkMailMan mailman;

    // Tell the mailman object to connect to the POP3 server though the ssh2 tunnel (which itself is routed through ssh1).
    // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => POP3Server
    success = mailman.UseSsh(ssh2);
    if (success != true) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    // Set the POP3 server's hostname
    mailman.put_MailHost("pop.someMailServer.com");

    // Set the POP3 login/password.
    mailman.put_PopUsername("myLogin");
    mailman.put_PopPassword("myPassword");

    // Establish the POP3 connection through the ssh2 tunnel.
    success = mailman.Pop3BeginSession();
    if (success != true) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    // Get the number of messages in the mailbox.
    int numMessages = mailman.GetMailboxCount();

    int i = 1;

    CkEmail *email = 0;
    while (i <= numMessages) {

        email = mailman.FetchByMsgnum(i);
        if (mailman.get_LastMethodSuccess() != true) {
            std::cout << mailman.lastErrorText() << "\r\n";
            return;
        }

        std::cout << email->ck_from() << ": " << email->subject() << "\n" << "\r\n";
        delete email;

        i = i + 1;
    }

    // Close the connection with the POP3 server.  (This closes the tunnel through ssh2)
    // The connection with ssh2 is still alive, and may be used for more connections.
    success = mailman.Pop3EndSession();

    // Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
    // The connection with ssh1 is still alive, and may be used for more connections.

    ssh2.Disconnect();

    ssh1.Disconnect();
    }