Delphi DLL

POP3 SSH Tunneling (Port Forwarding)

Demonstrates how to connect to a POP3 server through an SSH tunnel. Reads a POP3 mailbox and display the FROM and SUBJECT header fields of each email. Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mailman: HCkMailMan;
sshHostname: PWideChar;
sshPort: Integer;
numToDownload: Integer;
i: Integer;
email: HCkEmail;

begin
success := False;

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

// The mailman object is used for receiving (POP3) 
// and sending (SMTP) email.
mailman := CkMailMan_Create();

// 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 := 'sftp.example.com';
sshPort := 22;

// Connect to an SSH server and establish the SSH tunnel:
success := CkMailMan_SshOpenTunnel(mailman,sshHostname,sshPort);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    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 POP3 server, it is
// for authenticating with the SSH server, which is separate.
success := CkMailMan_SshAuthenticatePw(mailman,'ssh_login','ssh_password');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    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.

// The SSH tunnel may be kept open for any number of 
// POP3 connections.  

// Set the POP3 server's hostname
CkMailMan_putMailHost(mailman,'mail.my-pop3-server.com');

// Set the POP3 settings for your POP3 server:
CkMailMan_putPopUsername(mailman,'pop3_login');
CkMailMan_putPopPassword(mailman,'pop3_password');
CkMailMan_putMailPort(mailman,995);
CkMailMan_putPopSsl(mailman,True);

// Connect to the POP3 server through the already-established SSH tunnel:
success := CkMailMan_Pop3BeginSession(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// A visual inspection of the LastErrorText after
// a successful POP3 connection will confirm the SSH tunneling.
// Note: If the POP3 connection uses SSL/TLS, then the SSL/TLS 
// secure channel will be wrapped within the SSH tunnel.
Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));

// How many messages are in the POP3 inbox?
numToDownload := CkMailMan_GetMailboxCount(mailman);
if (numToDownload > 5) then
  begin
    numToDownload := 5;
  end;
if (numToDownload = 0) then
  begin
    Memo1.Lines.Add('No messages in the POP3 inbox.');
    Exit;
  end;

// Download a max of 5 messages

email := CkEmail_Create();
for i := 1 to numToDownload do
  begin
    success := CkMailMan_FetchOne(mailman,False,0,i,email);
    if (success = False) then
      begin
        Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
        Exit;
      end;

    Memo1.Lines.Add(CkEmail__from(email));
    Memo1.Lines.Add(CkEmail__subject(email));
    Memo1.Lines.Add('----');
  end;

// Close the connection with the POP3 server, leaving the SSH tunnel open for subsequent POP3 connections.
success := CkMailMan_Pop3EndSession(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Try connecting to a different POP3 server through the same aleady setup SSH tunnel:
// Set the POP3 server's hostname
CkMailMan_putMailHost(mailman,'mail.my-pop3-server2.com');

// Set the POP3 settings for your POP3 server:
CkMailMan_putPopUsername(mailman,'pop3_login2');
CkMailMan_putPopPassword(mailman,'pop3_password2');
CkMailMan_putMailPort(mailman,110);
CkMailMan_putPopSsl(mailman,False);

success := CkMailMan_Pop3BeginSession(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Review the LastErrorText to see that the connection was made via the SSH tunnel:
Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));

success := CkMailMan_Pop3EndSession(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Close the SSH tunnel.
success := CkMailMan_SshCloseTunnel(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);

end;