(Delphi ActiveX) Download an IMAP Message Set

Demonstrates how to read a set of IMAP emails.

Note: This example requires Chilkat v11.0.0 or greater.

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
success: Integer;
imap: TChilkatImap;
fetchUids: Integer;
messageSet: TMessageSet;
bundle: TChilkatEmailBundle;
headersOnly: Integer;
email: TChilkatEmail;
i: Integer;
numEmails: Integer;

begin
success := 0;

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

imap := TChilkatImap.Create(Self);

// Connect using TLS.
imap.Ssl := 1;
imap.Port := 993;
success := imap.Connect('imap.example.com');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Authenticate
success := imap.Login('email_account_login','email_account_password');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Select an IMAP mailbox
success := imap.SelectMailbox('Inbox');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Search for messages with the word "test" in the subject.
fetchUids := 1;

messageSet := TMessageSet.Create(Self);
success := imap.QueryMbx('Subject test',fetchUids,messageSet.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Download the messages in a single call to FetchMsgSet.
// 
// This only makes sense if the number of emails to be downloaded is not too large.  
// For example, you wouldn't want to download 10000 emails in a single call to FetchMsgSet.
// Why? For two reasons:  (1) It could potentially cause an out-of-memory condition, and 
// (2) it would take an extremely large amount of time.  The longer the amount of time,
// the greater the likelihood of some kind of external networking or server problem occuring,
// and if it happens, then you would need to re-download everything from the beginning again.
// For large numbers of emails, it's better to loop over the emails in the message set
// and download/process one at a time as shown here: Download IMAP Messages One at a Time
// Downloading one message at a time makes it possible to resume the downloads rather than restart the entire operation all over again.

// If the message set is reasonable in size, you can download all at once using FetchMsgSet:

Memo1.Lines.Add('Number of messages = ' + IntToStr(messageSet.Count));

bundle := TChilkatEmailBundle.Create(Self);
headersOnly := 0;
success := imap.FetchMsgSet(headersOnly,messageSet.ControlInterface,bundle.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Display the Subject and From of each email.
email := TChilkatEmail.Create(Self);
i := 0;
numEmails := bundle.MessageCount;
while i < numEmails do
  begin
    bundle.EmailAt(i,email.ControlInterface);

    Memo1.Lines.Add(email.GetHeaderField('Date'));
    Memo1.Lines.Add(email.Subject);
    Memo1.Lines.Add(email.From);
    Memo1.Lines.Add('--');
    i := i + 1;
  end;
end;