Pascal (Lazarus/Delphi)

How to Download Messages in MessageSet One at a Time

See more IMAP Examples

If a message set contains a huge number of emails, it's NOT a good idea to try to download all at once into an email bundle using a method such as FetchBundle. It's better to iterate over the messages in the set to download one by one. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Imap,
  Chilkat.Email,
  Chilkat.MessageSet;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  imap: TImap;
  fetchUids: Boolean;
  messageSet: TMessageSet;
  email: TEmail;
  i: Integer;

begin
  success := False;

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

  imap := TImap.Create;

  //  Connect using TLS.
  imap.Ssl := True;
  imap.Port := 993;
  success := imap.Connect('imap.example.com');
  if (success = False) then
    begin
      WriteLn(imap.LastErrorText);
      Exit;
    end;

  //  Authenticate
  success := imap.Login('email_account_login','email_account_password');
  if (success = False) then
    begin
      WriteLn(imap.LastErrorText);
      Exit;
    end;

  //  Select an IMAP mailbox
  success := imap.SelectMailbox('Inbox');
  if (success = False) then
    begin
      WriteLn(imap.LastErrorText);
      Exit;
    end;

  //  Search for messages and return a set of matching messages.
  //  (This example will simply search for ALL messages.)
  fetchUids := True;

  messageSet := TMessageSet.Create;
  success := imap.QueryMbx('ALL',fetchUids,messageSet);
  if (success = False) then
    begin
      WriteLn(imap.LastErrorText);
      Exit;
    end;

  WriteLn('Number of messages = ' + messageSet.Count);

  email := TEmail.Create;
  i := 0;
  while i < messageSet.Count do
    begin
      success := imap.FetchEmail(False,messageSet.GetId(i),fetchUids,email);
      if (success = False) then
        begin
          WriteLn(imap.LastErrorText);
          Exit;
        end;

      WriteLn(email.From + '; ' + email.Subject);

      i := i + 1;
    end;

  WriteLn('OK');


  imap.Free;
  messageSet.Free;
  email.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.