(Delphi ActiveX) Auto-Generate or Explicitly Specify the Message-ID Email Header

Demonstrates how to auto-generate or explicitly specify the Message-ID header field.

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
email: TChilkatEmail;
success: Integer;
mailman: TChilkatMailMan;
mimeStr: WideString;

begin
email := TChilkatEmail.Create(Self);

email.Subject := 'test';
email.Body := 'test';
email.AddTo('Joe','joe@example1.com');
email.From := 'mary@example2.com';

mailman := TChilkatMailMan.Create(Self);

// When the mailman sends email, it renders the email to be sent,
// and then sends the rendered MIME.

// Instead of actually sending the email, this example will render
// to MIME so we can see what would be sent..

// We can explicitly set the Message-ID like this:
mailman.AutoGenMessageId := 0;
email.AddHeaderField('Message-ID','<xyz123@abc>');

mimeStr := mailman.RenderToMime(email.ControlInterface);
Memo1.Lines.Add(mimeStr);

// This is what we get:

// MIME-Version: 1.0
// Date: Mon, 20 Jul 2020 17:20:09 -0500
// Message-ID: <xyz123@abc>
// Content-Type: text/plain; charset=us-ascii; format=flowed
// Content-Transfer-Encoding: 7bit
// X-Priority: 3 (Normal)
// Subject: test
// To: Joe <joe@example1.com>
// From: mary@example2.com
// 
// test

Memo1.Lines.Add('--------');

// If we auto-generate...
mailman.AutoGenMessageId := 1;
mimeStr := mailman.RenderToMime(email.ControlInterface);
Memo1.Lines.Add(mimeStr);

// We get this:

// MIME-Version: 1.0
// Date: Mon, 20 Jul 2020 17:21:20 -0500
// Message-ID: <04EDE096BBFE484967F6398A973B0FCF6EA09A44@CHILKATSLICE>
// Content-Type: text/plain; charset=us-ascii; format=flowed
// Content-Transfer-Encoding: 7bit
// X-Priority: 3 (Normal)
// Subject: test
// To: Joe <joe@example1.com>
// From: mary@example2.com
// 
// test
end;