(Delphi ActiveX) Process Large POP3 Mailbox

Demonstrates how to read email from a mailbox that may contain a large number of emails.

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
mailman: TChilkatMailMan;
sa: ICkStringArray;
i: Integer;
numEmails: Integer;
chunkSize: Integer;
chunkBeginIdx: Integer;
chunkEndIdx: Integer;
saChunk: TCkStringArray;
chunkStr: WideString;
bundle: IChilkatEmailBundle;

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

mailman := TChilkatMailMan.Create(Self);

mailman.MailHost := 'pop.example.com';

mailman.PopUsername := 'myLogin';
mailman.PopPassword := 'myPassword';

mailman.MailPort := 995;
mailman.PopSsl := 1;

// Get the list of UIDLs for all emails in the mailbox.
sa := mailman.GetUidls();
if (mailman.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

numEmails := sa.Count;
if (numEmails = 0) then
  begin
    Memo1.Lines.Add('Mailbox is empty');
    Exit;
  end;

chunkSize := 6;

// Download the emails in chunks of 6 emails each.
chunkBeginIdx := 0;
chunkEndIdx := chunkSize - 1;
if (chunkEndIdx >= numEmails) then
  begin
    chunkEndIdx := numEmails - 1;
  end;

saChunk := TCkStringArray.Create(Self);
while (chunkBeginIdx < numEmails) do
  begin

    Memo1.Lines.Add(IntToStr(chunkBeginIdx) + ' to ' + IntToStr(chunkEndIdx));

    // Build a chunk of UIDLs.
    saChunk.Clear();
    for i := chunkBeginIdx to chunkEndIdx do
      begin
        saChunk.Append(sa.GetString(i));
      end;

    // Log the UIDLs in this chunk...
    chunkStr := saChunk.SaveToText();
    Memo1.Lines.Add(chunkStr);

    // Download this chunk of email from the POP3 server.
    bundle := mailman.FetchMultiple(saChunk.ControlInterface);
    if (mailman.LastMethodSuccess = 0) then
      begin
        Memo1.Lines.Add(mailman.LastErrorText);
        Exit;
      end;

    Memo1.Lines.Add('Downloaded ' + IntToStr(bundle.MessageCount) + ' emails.');
    Memo1.Lines.Add('----');

    // Process the bundle...
    // (your application's processing code goes here...)

    // Get the next chunk...
    chunkBeginIdx := chunkBeginIdx + chunkSize;
    chunkEndIdx := chunkEndIdx + chunkSize;
    if (chunkEndIdx >= numEmails) then
      begin
        chunkEndIdx := numEmails - 1;
      end;

  end;
end;