(Delphi DLL) 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 non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, MailMan, StringArray, EmailBundle;

...

procedure TForm1.Button1Click(Sender: TObject);
var
mailman: HCkMailMan;
sa: HCkStringArray;
i: Integer;
numEmails: Integer;
chunkSize: Integer;
chunkBeginIdx: Integer;
chunkEndIdx: Integer;
saChunk: HCkStringArray;
chunkStr: PWideChar;
bundle: HCkEmailBundle;

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

mailman := CkMailMan_Create();

CkMailMan_putMailHost(mailman,'pop.example.com');

CkMailMan_putPopUsername(mailman,'myLogin');
CkMailMan_putPopPassword(mailman,'myPassword');

CkMailMan_putMailPort(mailman,995);
CkMailMan_putPopSsl(mailman,True);

// Get the list of UIDLs for all emails in the mailbox.
sa := CkMailMan_GetUidls(mailman);
if (CkMailMan_getLastMethodSuccess(mailman) = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

numEmails := CkStringArray_getCount(sa);
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 := CkStringArray_Create();
while (chunkBeginIdx < numEmails) do
  begin

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

    // Build a chunk of UIDLs.
    CkStringArray_Clear(saChunk);
    for i := chunkBeginIdx to chunkEndIdx do
      begin
        CkStringArray_Append(saChunk,CkStringArray__getString(sa,i));
      end;

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

    // Download this chunk of email from the POP3 server.
    bundle := CkMailMan_FetchMultiple(mailman,saChunk);
    if (CkMailMan_getLastMethodSuccess(mailman) = False) then
      begin
        Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
        Exit;
      end;

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

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

    CkEmailBundle_Dispose(bundle);

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

  end;

CkStringArray_Dispose(sa);

CkMailMan_Dispose(mailman);
CkStringArray_Dispose(saChunk);

end;