(Delphi ActiveX) SMTP over Multiple Hop SSH

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

Application => ServerSSH1 => ServerSSH2 => SmtpServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh1: TChilkatSsh;
success: Integer;
ssh2: TChilkatSsh;
mailman: TChilkatMailMan;
email: TChilkatEmail;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

ssh1 := TChilkatSsh.Create(Self);

// Connect directly to the 1st SSH server.
success := ssh1.Connect('serverssh1.com',22);
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh1.LastErrorText);
    Exit;
  end;

// Authenticate using login/password:
success := ssh1.AuthenticatePw('ssh1Login','ssh1Password');
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh1.LastErrorText);
    Exit;
  end;

// 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.
ssh2 := TChilkatSsh.Create(Self);
success := ssh2.ConnectThroughSsh(ssh1.ControlInterface,'serverssh2.com',22);
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh2.LastErrorText);
    Exit;
  end;

// Authenticate with ssh2...
success := ssh2.AuthenticatePw('ssh2Login','ssh2Password');
if (success <> 1) then
  begin
    Memo1.Lines.Add(ssh2.LastErrorText);
    Exit;
  end;

mailman := TChilkatMailMan.Create(Self);

// Tell the mailman object to connect to the SMTP server though the ssh2 tunnel (which itself is routed through ssh1).
// The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => SMTPServer
success := mailman.UseSsh(ssh2.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

// Set the SMTP server.
mailman.SmtpHost := 'smtp.someserver.com';

// Set the SMTP login/password (if required)
mailman.SmtpUsername := 'myUsername';
mailman.SmtpPassword := 'myPassword';

// Create a new email object
email := TChilkatEmail.Create(Self);

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

success := mailman.SendEmail(email.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

// Close the connection with the server.  This closes the tunnel through ssh2.
success := mailman.CloseSmtpConnection();
if (success <> 1) then
  begin
    Memo1.Lines.Add('Connection to SMTP server not closed cleanly.');
  end;

Memo1.Lines.Add('Mail Sent!');

// 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();
end;