Send Email with Multiple Threads(Mass Mail) in Delphi

In previous section, I introduced how to use asynchronous mode. In this section, I will introduce how to send mass email with multiple threads in Delphi.

Introduction

FastSender object has an inner threading pool based on MaxThreads count. Firstly, Send method submits email to FastSender mail queue. Secondly threading pool retrieves email from mail queue and sends it out. Finally OnSent event informs that the email was sent successfully or unsuccessfully.

No. of worker threads in the threading pool of FastSender object is automatically adjusted based on the actual usage. The maximum no. of worker threads is up to the value of MaxThread property specified.

Note

Remarks: All of samples in this section are based on first section: Send email in a simple Delphi project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference of EASendMail to your project.

[Delphi - Send mass email with multiple threads - Example]

The following example codes demonstrate how to send mass email with multiple threads in Delphi.

Note

To get the full sample projects, please refer to Samples section.

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;
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';

  // If your SMTP server requires SSL connection, please add this line
  // oSmtp.SSL_init();

  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.

Next Section

At next section I will introduce how to send email using EASendMail Service Queue in Delphi.

Appendix

Comments

If you have any comments or questions about above example codes, please click here to add your comments.