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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use chilkat();

#  The mailman object is used for sending (SMTP) and receiving (POP3) email.
$mailman = new chilkat::CkMailMan();

#  Any string argument automatically begins the 30-day trial.
$success = $mailman->UnlockComponent("30-day trial.");
if ($success != 1) {
    print "Component unlock failed" . "\n";
    exit;
}

#  Connect to an SSH server and establish the SSH tunnel:

#  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 = 1;
#  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 != 1) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

#  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 != 1) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

#  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->put_SmtpHost("smtp.chilkatsoft.com");

#  Set the SMTP login/password (if required)
$mailman->put_SmtpUsername("smtpLogin");
$mailman->put_SmtpPassword("smtpPassword");

#  Create a new email object
$email = new chilkat::CkEmail();

$email->put_Subject("This is a test");
$email->put_Body("This is a test");
$email->put_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 != 1) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

#  If you're curious, have a look at LastErrorText after
#  a successful send.  You'll see detailed information that
#  confirms the SSH tunneling.
print $mailman->lastErrorText() . "\n";

#  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.

print "Mail Sent!" . "\n";