Delphi - Download Email in Background

In an ASP/ASP.NET email application, if email download takes longer than the timeout value (in seconds) that the current asp page is allowed to run, user will get an error “ASP Timeout”. This often happens when user has a large quantity of emails to download or user downloads emails via a slow connection. By default the timeout is set to 90 seconds, it is easy to exceed this limit.

Obviously, a solution to ASP timeout is to set ASPScriptTimeout a larger value. You may click here for details. Technically the timeout problem can be solved in this way; however, some users may get frustrated and press the stop button on the browser toolbar as he waits too long.

EAGetMail POP3 Component introduces a more intelligent method to retrieve emails in background. You should download the EAGetMail Service installer and install it on your machine at first. Then you can use MailClient.GetMailsByQueue method to send the request to EAGetMail Service, the method returns to the user immediately and the EAGetMail Service performs task in background.

Important

To run the following example, you need to download EAGetMail and EAGetMail Service at first, and then install both on your machine.

The following delphi example codes demonstrate how to download email from POP3 server in background.

Installation

Before you can use the following sample codes, you should download the EAGetMail Installer and install it on your machine at first. Full sample projects are included in this installer.

Add Reference

To use EAGetMail ActiveX Object in your Delphi project, the first step is “Add Unit file of EAGetMail to your project”. Please go to C:\Program Files\EAGetMail\Samples_Delphi\pop3_imap4_simple.delphi or C:\Program Files (x86)\EAGetMail\Samples_Delphi\pop3_imap4_simple.delphi folder, find EAGetMailObjLib_TLB.pas, and then copy this file to your project folder.

// include EAGetMailObjLib_TLB unit to your Delphi Project
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, EAGetMailObjLib_TLB, StdCtrls;

Then you can start to use it in your Delphi Project.

You can also create EAGetMailObjLib_TLB.pas manually by Delphi like this:

  • Delphi 7 or eariler version

    First of all, create a standard delphi project: select menu Project -> Import Type Library, checked EAGetMail ActiveX Object and click Create Unit. Then include EAGetMailObjLib_TLB in your project.

    add reference in Delphi
  • Delphi XE or later version

    First of all, create a standard delphi project: select menu Component -> Import component... -> Import a type library -> checked EAGetMail ActiveX Object, have Generate Component Wrapper checked and click “Create Unit”. Then include EAGetMailObjLib_TLB in your project.

Delphi - Download Email in Background - Example

The following example codes demonstrate downloading email from POP3 server in background. In order to run it correctly, please change email server, user, password, folder, file name value to yours.

Note

To get full sample projects, please download and install EAGetMail on your machine.

Unit Unit1;

Interface

Uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls, EAGetMailObjLib_TLB;

Type
    TForm1 = Class(TForm)
        Button1: TButton;
        Procedure Button1Click(Sender: TObject);
    private
        { Private declarations }
    public
        { Public declarations }
    End;

Const
    MailServerPop3 = 0;
    MailServerImap4 = 1;

Var
    Form1: TForm1;

Implementation

{$R *.dfm}

Procedure TForm1.Button1Click(Sender: TObject);
Var
    oClient: TMailClient;
    oServer: TMailServer;
    oTools: TTools;
    mailFolder: WideString;
    leaveCopy: Boolean;
Begin
    Try
        oTools := TTools.Create(Application);

        // Create a folder named "inbox" under
        // current directory to store the email files
        mailFolder := GetCurrentDir() + '\inbox';
        oTools.CreateFolder(mailFolder);

        oServer := TMailServer.Create(Application);
        oServer.Server := 'pop3.emailarchitect.net';
        oServer.User := 'test@emailarchitect.net';
        oServer.Password := 'testpassword';
        oServer.Protocol := MailServerPop3;

        // If your server requires SSL connection
        // Please add the following codes
        // oServer.SSLConnection := true;
        // oServer.Port := 995;

        // Leave a copy of message
        leaveCopy := true;

        oClient := TMailClient.Create(Application);
        oClient.LicenseCode := 'TryIt';

        // Send request to EAGetMail Service, then EAGetMail Service retrieves email
        // in background and this method returns immediately.
        oClient.GetMailsByQueue(oServer.DefaultInterface, mailFolder, leaveCopy);

    Except
        On ep:Exception Do
        ShowMessage('Error: ' + ep.Message);
    End;
End;

End.

32bit/x64 ActiveX DLL

Seperate builds of run-time dll for 32 and x64 platform

File Platform
Installation Path\EAGetMailObj.dll 32 bit
Installation Path\x64\EAGetMailObj.dll 64 bit

Distribution

  • Standard EXE

    For VB6, C++, Delphi or other standard exe application, you can distribute EAGetMailObj.dll with your application to target machine without COM-registration and installer. To learn more detail, please have a look at Registration-free COM with Manifest File.

  • Script

    For ASP, VBScript, VBA, MS SQL Stored Procedure, you need to install EAGetMail on target machine by EAGetMail installer, both 32bit/x64 DLL are installed and registered.

Appendix

Comments

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