SMTP SSH Tunneling (Port Forwarding)

Demonstrates how to setup an SSH tunnel for SMTP. This example connects to an SMTP sever via an SSH tunnel and sends an email.

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//  The mailman object is used for sending (SMTP) and receiving (POP3) email.
Chilkat.MailMan mailman = new Chilkat.MailMan();

//  Any string argument automatically begins the 30-day trial.
bool success;
success = mailman.UnlockComponent("30-day trial.");
if (success != true) {
    MessageBox.Show("Component unlock failed");
    return;
}

//  Connect to an SSH server and establish the SSH tunnel:
string sshHostname;
int sshPort;
bool bSmtp;
//  The SSH hostname may be a hostname or an
//  IP address, such as "192.168.1.108".
//  The port is typically 22 (the standard port for SSH).
sshHostname = "www.my-ssh-server.com";
sshPort = 22;
bSmtp = true;
//  The 1st argument passed to SshTunnel indicates whether
//  a tunnel for SMTP or POP3 is being established.
success = mailman.SshTunnel(bSmtp,sshHostname,sshPort);
if (success != true) {
    MessageBox.Show(mailman.LastErrorText);
    return;
}

//  Authenticate with the SSH server via a login/password
//  or with a public key.
//  This example demonstrates SSH password authentication.
//  Note: This is not authenticating with the SMTP server, it is
//  for authenticating with the SSH server, which is separate.
success = mailman.SshAuthenticatePw(bSmtp,"sshLogin","sshPassword");
if (success != true) {
    MessageBox.Show(mailman.LastErrorText);
    return;
}

//  OK, the SSH tunnel is setup.  The mailman may
//  be used exactly the same as usual, except all communications
//  are now sent through the SSH tunnel.

//  Set the SMTP server.
mailman.SmtpHost = "smtp.chilkatsoft.com";

//  Set the SMTP login/password (if required)
mailman.SmtpUsername = "smtpLogin";
mailman.SmtpPassword = "smtpPassword";

//  Create a new email object
Chilkat.Email email = new Chilkat.Email();

email.Subject = "This is a test";
email.Body = "This is a test";
email.From = "Chilkat Support <support@chilkatsoft.com>";
email.AddTo("Chilkat Admin","admin@chilkatsoft.com");

//  The call to SendEmail automatically connects to the SMTP
//  server via the SSH tunnel (if not already connected).
//  Because the SSH tunnel has been previously setup,
//  this does not establish a direct connection with the SMTP
//  server.  It directs the SSH server to establish the connection.

//  After SendEmail completes, the connection (i.e. session) remains
//  open so that subsequent SendEmail calls may use the
//  same SSH tunnel.
success = mailman.SendEmail(email);
if (success != true) {
    MessageBox.Show(mailman.LastErrorText);
    return;
}

//  If you're curious, have a look at LastErrorText after
//  a successful send.  You'll see detailed information that
//  confirms the SSH tunneling.
MessageBox.Show(mailman.LastErrorText);

//  Note: Some SMTP servers do not actually send the email until
//  the connection is closed.  In these cases, it is necessary to
//  call CloseSmtpConnection for the mail to be  sent.
//  Most SMTP servers send the email immediately, and it is
//  not required to close the connection.

MessageBox.Show("Mail Sent!");