(Delphi DLL) 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 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, EmailBundle, Imap, Email, MessageSet;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
imap: HCkImap;
fetchUids: Boolean;
messageSet: HCkMessageSet;
bundle: HCkEmailBundle;
headersOnly: Boolean;
email: HCkEmail;
i: Integer;
numEmails: Integer;

begin
success := False;

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

imap := CkImap_Create();

// Connect using TLS.
CkImap_putSsl(imap,True);
CkImap_putPort(imap,993);
success := CkImap_Connect(imap,'imap.example.com');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Authenticate
success := CkImap_Login(imap,'email_account_login','email_account_password');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Select an IMAP mailbox
success := CkImap_SelectMailbox(imap,'Inbox');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

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

messageSet := CkMessageSet_Create();
success := CkImap_QueryMbx(imap,'Subject test',fetchUids,messageSet);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    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(CkMessageSet_getCount(messageSet)));

bundle := CkEmailBundle_Create();
headersOnly := False;
success := CkImap_FetchMsgSet(imap,headersOnly,messageSet,bundle);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Display the Subject and From of each email.
email := CkEmail_Create();
i := 0;
numEmails := CkEmailBundle_getMessageCount(bundle);
while i < numEmails do
  begin
    CkEmailBundle_EmailAt(bundle,i,email);

    Memo1.Lines.Add(CkEmail__getHeaderField(email,'Date'));
    Memo1.Lines.Add(CkEmail__subject(email));
    Memo1.Lines.Add(CkEmail__from(email));
    Memo1.Lines.Add('--');
    i := i + 1;
  end;

CkImap_Dispose(imap);
CkMessageSet_Dispose(messageSet);
CkEmailBundle_Dispose(bundle);
CkEmail_Dispose(email);

end;