Send Email with Multiple Threads(Mass Mail) in Delphi¶

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, EASendMailObjLib_TLB; // add EASendMail unit
type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    // FastSender event handler
    procedure OnSent(ASender: TObject; lRet: Integer; const ErrDesc: WideString;
    nKey: Integer; const tParam: WideString;
    const senderAddr: WideString;
    const Recipients: WideString);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

const
  ConnectNormal = 0;
  ConnectSSLAuto = 1;
  ConnectSTARTTLS = 2;
  ConnectDirectSSL = 3;
  ConnectTryTLS = 4;

var
  Form1: TForm1;
  m_oFastSender: TFastSender;

implementation

{$R *.dfm}

procedure TForm1.OnSent(ASender: TObject; lRet: Integer; const ErrDesc: WideString;
    nKey: Integer; const tParam: WideString;
    const senderAddr: WideString;
    const Recipients: WideString);
begin
    if lRet = 0 then
      ShowMessage(Format('%d email was sent successfully', [nKey]))
    else
      ShowMessage(Format('%d: faile to send email: ' + ErrDesc, [nKey]));
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  oSmtp: TMail;
  RecipientAddr: array[0..2] of WideString;
  i: Integer;
begin
  if m_oFastSender = nil then
  begin
    m_oFastSender := TFastSender.Create(Application);
    oSmtp := TMail.Create(Application);
    oSmtp.LicenseCode := 'TryIt';

    // Attach FastSender event handler
    m_oFastSender.OnSent := OnSent;
    // Set maximum number of worker threads
    m_oFastSender.MaxThreads := 10;
  end;

  // Set your sender email address
  oSmtp.FromAddr := 'test@emailarchitect.net';
  // Set recpient addresses
  RecipientAddr[0] := 'test@adminsystem.com';
  RecipientAddr[1] := 'test1@adminsystem.com';
  RecipientAddr[2] := 'test2@adminsystem.com';

  // Your SMTP server address
  oSmtp.ServerAddr := 'smtp.emailarchitect.net';
  // User and password for ESMTP authentication, if your server doesn't require
  // user authentication, please remove the following codes
  oSmtp.UserName := 'test@emailarchitect.net';
  oSmtp.Password := 'testpassword';

  // ConnectTryTLS means if server supports SSL/TLS connection, SSL/TLS is used automatically
  oSmtp.ConnectType := ConnectTryTLS;

  // If your server uses 587 port
  // oSmtp.ServerPort := 587;

  // If your server uses 25/587/465 port with SSL/TLS
  // oSmtp.ConnectType := ConnectSSLAuto;
  // oSmtp.ServerPort := 587; // 25 or 587 or 465

  for i := 0 to 2 do
  begin
    oSmtp.ClearRecipient();
    oSmtp.AddRecipientEx(RecipientAddr[i], 0);
    oSmtp.Subject := 'mass email test subject';
    oSmtp.BodyText := 'mass email test body from delphi';

    m_oFastSender.Send(oSmtp.DefaultInterface, i, RecipientAddr[i])
  end;

end;

end.