Pascal (Lazarus/Delphi)

Send DKIM Signed Email

See more DKIM / DomainKey Examples

Demonstrates how to send DKIM signed email. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.MailMan,
  Chilkat.BinData,
  Chilkat.PrivateKey,
  Chilkat.Email,
  Chilkat.Dkim;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  mailman: TMailMan;
  dkim: TDkim;
  email: TEmail;
  bdMime: TBinData;
  password: string;
  privKey: TPrivateKey;
  strRecipients: string;
  strFrom: string;

begin
  success := False;

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

  mailman := TMailMan.Create;
  dkim := TDkim.Create;

  //  SMTP server settings...
  mailman.SmtpHost := 'SMTP_DOMAIN';
  mailman.SmtpUsername := 'SMTP_LOGIN';
  mailman.SmtpPassword := 'SMTP_PASSWORD';
  mailman.SmtpPort := 465;
  mailman.SmtpSsl := True;

  email := TEmail.Create;

  email.Subject := 'This is a test';
  email.Body := 'This is a test';
  email.From := 'Chilkat Support <support@chilkatsoft.com>';

  //  Add some recipients (BCC recipients are added below)
  email.AddTo('Chilkat Software','chilkat_software@yahoo.com');
  email.AddTo('Chilkat Admin','admin@chilkatsoft.com');
  email.AddCC('Chilkat Admin','admin@chilkat.io');

  //  When sending an email with a DKIM signature, the MIME
  //  of the email must not be modified prior to
  //  or during the sending process.  Therefore, the MIME of the
  //  email is assembled, the DKIM signature is added, and then
  //  SendMimeBd is called to send the email.

  //  First get the MIME of the email.  Calling RenderToMimeBd 
  //  causes the email to be signed and/or encrypted if those options
  //  have been selected.  The MIME returned by RenderToMimeBd
  //  is the exact MIME that would've been sent if SendEmail was
  //  called.  We'll add a DKIM signature header to this MIME and then send...
  bdMime := TBinData.Create;
  success := mailman.RenderToMimeBd(email,bdMime);
  if (success = False) then
    begin
      WriteLn(mailman.LastErrorText);
      Exit;
    end;

  //  To create a DKIM signature,
  //  you'll need to provide the following:
  //  (1) An RSA private key in any common file format.
  //  (2) The domain name (typically the same domain
  //  as the sender of an email).
  //  (3) A selector for the domain name -- an arbitrary string
  //  to identify the matching public key in DNS.

  //  To allow an email recipient to verify the DKIM signature via an
  //  external email client supporting DKIM or using other software,
  //  you will need to create a DNS record with the selector
  //  and matching public key.  This example does not provide
  //  information about DKIM DNS record creation.  
  //  (Chilkat does not provide an API for creating DNS records.  
  //  Creating the DKIM DNS record is something you would do
  //  manually.)

  //  Set the domain and selector:
  //  You'll need to provide your own values here..
  dkim.DkimDomain := 'chilkatsoft.com';
  dkim.DkimSelector := 'brisbane';

  //  Load a private key from any common RSA private key
  //  format, such as DER, PKCS8, PEM, XML, etc.
  //  The LoadDkimPkFile method automatically detects
  //  the file format and reads it appropriately.
  //  If a password is not required, you'll still need to provide
  //  an empty password string argument, but it is ignored.
  password := 'passwd';
  privKey := TPrivateKey.Create;
  success := privKey.LoadAnyFormatFile('qa_data/pem/rsa_passwd.pem',password);
  if (success = False) then
    begin
      WriteLn(privKey.LastErrorText);
      Exit;
    end;

  success := dkim.SetDkimPrivateKey(privKey);
  if (success = False) then
    begin
      WriteLn(dkim.LastErrorText);
      Exit;
    end;

  //  Add the DKIM-Signature header to the MIME in bdMime
  success := dkim.DkimSign(bdMime);
  if (success = False) then
    begin
      WriteLn(dkim.LastErrorText);
      Exit;
    end;

  //  If desired, examine the MIME of the email being sent.
  bdMime.WriteFile('qa_output/dkimSigned.eml');

  //  ---- Prepare to send the email contained in bdMime ---

  //  To send to multiple email addresses, the strRecipients should be set to a comma-separated
  //  list of email addresses.

  //  Note: This is where we can add additional BCC addreses.
  //  Here we are adding "chilkat.support@gmail.com" as an additional BCC address.
  //  Notice that the 1st three email addresses are NOT BCC because these email addresses
  //  appear in the MIME header of the email (in the "To" and "CC" header fields).
  //  A BCC email address does not appear in the MIME, and thus the non-BCC recipients cannot see
  //  that the email was also sent to the BCC address.  (BCC means "blind carbon copy")
  strRecipients := 'chilkat_software@yahoo.com, admin@chilkatsoft.com, admin@chilkat.io, chilkat.support@gmail.com';
  strFrom := 'support@chilkatsoft.com';

  success := mailman.SendMimeBd(strFrom,strRecipients,bdMime);
  if (success = False) then
    begin
      WriteLn(mailman.LastErrorText);
      Exit;
    end;

  success := mailman.CloseSmtpConnection();
  if (success <> True) then
    begin
      WriteLn('Connection to SMTP server not closed cleanly.');
    end;

  WriteLn('DKIM Signed Mail Sent!');


  mailman.Free;
  dkim.Free;
  email.Free;
  bdMime.Free;
  privKey.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.