Delphi DLL

POP3 GMail XOAUTH2 Authentication

See more GMail SMTP/IMAP/POP Examples

Demonstrates using OAuth2 authentication with pop.gmail.com.

Note: This example requires Chilkat v9.5.0.83 or greater.

Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mailman: HCkMailMan;
jsonToken: HCkJsonObject;
numEmails: Integer;

begin
success := False;

// 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.gmail.com');
CkMailMan_putMailPort(mailman,995);
CkMailMan_putPopSsl(mailman,True);

CkMailMan_putPopUsername(mailman,'my_account@gmail.com');

// If using OAuth2 authentication, leave the password empty.
CkMailMan_putPopPassword(mailman,'');

// Load our previously obtained OAuth2 access token.
// See Getting a GMail POP3 OAuth2 Access Token
jsonToken := CkJsonObject_Create();
success := CkJsonObject_LoadFile(jsonToken,'qa_data/tokens/gmail_pop3.json');
if (success = False) then
  begin
    Memo1.Lines.Add(CkJsonObject__lastErrorText(jsonToken));
    Exit;
  end;

CkMailMan_putOAuth2AccessToken(mailman,CkJsonObject__stringOf(jsonToken,'access_token'));

// Make the TLS connection to the POP3 server.
success := CkMailMan_Pop3Connect(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Authenticate..
success := CkMailMan_Pop3Authenticate(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Find out how many emails are on the server..
numEmails := CkMailMan_CheckMail(mailman);
if (numEmails < 0) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Examine the POP3 session log:
Memo1.Lines.Add(CkMailMan__pop3SessionLog(mailman));

// The POP3 session log will look something like this:

// **** Connected to pop.gmail.com:995
// < +OK Gpop ready for requests from 87.9.200.42 l16mb86351205iok
// > AUTH XOAUTH2 dXNlcj1....VaMDJFAQE=
// < +OK Welcome.
// > STAT
// < +OK 301 1627357
// 
// -- Finished.

// End the POP3 session and close the connection to the GMail server.
success := CkMailMan_Pop3EndSession(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

Memo1.Lines.Add('-- Finished.');

CkMailMan_Dispose(mailman);
CkJsonObject_Dispose(jsonToken);

end;