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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uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATMAILLib2_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
mailman: TChilkatMailMan2;
success: Integer;
sshHostname: String;
sshPort: Integer;
bSmtp: Integer;
email: CHILKATMAILLib2_TLB.IChilkatEmail2;

begin
//  The mailman object is used for sending (SMTP) and receiving (POP3) email.
mailman := TChilkatMailMan2.Create(Self);

//  Any string argument automatically begins the 30-day trial.
success := mailman.UnlockComponent('30-day trial.');
if (success <> 1) then
  begin
    ShowMessage('Component unlock failed');
    Exit;
  end;

//  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) then
  begin
    ShowMessage(mailman.LastErrorText);
    Exit;
  end;

//  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) then
  begin
    ShowMessage(mailman.LastErrorText);
    Exit;
  end;

//  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
email := CoChilkatEmail2.Create();

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 As CHILKATMAILLib2_TLB.IChilkatEmail2);
if (success <> 1) then
  begin
    ShowMessage(mailman.LastErrorText);
    Exit;
  end;

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

ShowMessage('Mail Sent!');
end;