(Delphi ActiveX) POP3 Auto-Refresh Office365 Access Token

See more Office365 Examples

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
mailman: TChilkatMailMan;
jsonToken: TChilkatJsonObject;
success: Integer;
oauth2: TChilkatOAuth2;
sbJson: TChilkatStringBuilder;
numEmails: Integer;

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

mailman := TChilkatMailMan.Create(Self);

mailman.MailHost := 'outlook.office365.com';
mailman.MailPort := 995;
mailman.PopSsl := 1;

// Use your O365 email address here.
mailman.PopUsername := 'OFFICE365_EMAIL_ADDRESS';

// When using OAuth2 authentication, leave the password empty.
mailman.PopPassword := '';

// Load our previously obtained OAuth2 access token.
jsonToken := TChilkatJsonObject.Create(Self);
success := jsonToken.LoadFile('qa_data/tokens/office365.json');
if (success = 0) then
  begin
    Memo1.Lines.Add(jsonToken.LastErrorText);
    Exit;
  end;

mailman.OAuth2AccessToken := jsonToken.StringOf('access_token');

// Make the TLS connection to the outlook.office365.com POP3 server.
success := mailman.Pop3Connect();
if (success <> 1) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

// Authenticate using XOAUTH2
success := mailman.Pop3Authenticate();
if (success <> 1) then
  begin
    // If we're still connected to the mail server, then it means the server sent a non-success response,
    // Such as:  -ERR Authentication failure: unknown user name or bad password.
    if (mailman.IsPop3Connected = 1) then
      begin

        // Refresh the OAuth2 access token, and if successful, save the new (refreshed) access token and try authenticating again.
        oauth2 := TChilkatOAuth2.Create(Self);

        // Use your actual Directory (tenant) ID instead of "112d7ed6-71bf-4eba-a866-738364321bfc"
        oauth2.TokenEndpoint := 'https://login.microsoftonline.com/112d7ed6-71bf-4eba-a866-738364321bfc/oauth2/v2.0/token';

        // Replace these with your Azure App Registration's actual values.
        oauth2.ClientId := 'CLIENT_ID';
        oauth2.ClientSecret := 'CLIENT_SECRET';

        // Get the "refresh_token"
        oauth2.RefreshToken := jsonToken.StringOf('refresh_token');

        // Send the HTTP POST to refresh the access token..
        success := oauth2.RefreshAccessToken();
        if (success <> 1) then
          begin
            Memo1.Lines.Add(oauth2.LastErrorText);
            Exit;
          end;

        Memo1.Lines.Add('New access token: ' + oauth2.AccessToken);
        Memo1.Lines.Add('New refresh token: ' + oauth2.RefreshToken);

        // Update the JSON with the new tokens.
        jsonToken.UpdateString('access_token',oauth2.AccessToken);
        jsonToken.UpdateString('refresh_token',oauth2.RefreshToken);

        // Save the new JSON access token response to a file.
        sbJson := TChilkatStringBuilder.Create(Self);
        jsonToken.EmitCompact := 0;
        jsonToken.EmitSb(sbJson.ControlInterface);
        sbJson.WriteFile('qa_data/tokens/office365.json','utf-8',0);

        Memo1.Lines.Add('New Access Token = ' + oauth2.AccessToken);

        // Update the mailman with the new access token.
        mailman.OAuth2AccessToken := oauth2.AccessToken;

        // Retry the authentication.
        success := mailman.Pop3Authenticate();
        if (success = 0) then
          begin
            Memo1.Lines.Add(mailman.LastErrorText);
            Exit;
          end;

      end
    else
      begin
        Memo1.Lines.Add(mailman.LastErrorText);
        Exit;
      end;
  end;

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

// Examine the POP3 session log:
Memo1.Lines.Add(mailman.Pop3SessionLog);

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

// **** Connected to outlook.office365.com:995
// < +OK The Microsoft Exchange POP3 service is ready. [QwBIADIAUABSADEANgBDAEEAMAAwADEAMgAuAG4AYQBtAHAAcgBkADEANgAuAHAAcgBvAGQALgBvAHUAdABsAG8AbwBrAC4AYwBvAG0A]
// > AUTH XOAUTH2
// < + 
// > <base64 string in XOAUTH2 format>
// < -ERR Authentication failure: unknown user name or bad password.
// > AUTH XOAUTH2
// < + 
// > <base64 string in XOAUTH2 format>
// < +OK User successfully authenticated.
// > STAT
// < +OK 248 46637086

// End the POP3 session and close the connection to the GMail server.
success := mailman.Pop3EndSession();
if (success <> 1) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

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