Delphi - Retrieve Email using Microsoft OAuth 2.0 (Modern Authentication) + EWS Protocol from Office 365 in Background Service¶

// include EAGetMailObjLib_TLB unit to your Delphi Project
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, EAGetMailObjLib_TLB, StdCtrls;

program Project1;
{$APPTYPE CONSOLE}

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, ActiveX, MSXML2_TLB, EAGetMailObjLib_TLB;

const
    MailServerPop3 = 0;
    MailServerImap4 = 1;
    MailServerEWS = 2;
    MailServerDAV = 3;

    // Auth type
    MailServerAuthLogin = 0;
    MailServerAuthCRAM5 = 1;
    MailServerAuthNTLM = 2;
    MailServerAuthXOAUTH2 = 3;

    CRYPT_MACHINE_KEYSET = 32;
    CRYPT_USER_KEYSET = 4096;
    CERT_SYSTEM_STORE_CURRENT_USER = 65536;
    CERT_SYSTEM_STORE_LOCAL_MACHINE = 131072;

    // GetMailInfosParam Flags
    GetMailInfos_All = 1;
    GetMailInfos_NewOnly = 2;
    GetMailInfos_ReadOnly = 4;
    GetMailInfos_SeqRange = 8;
    GetMailInfos_UIDRange = 16;
    GetMailInfos_PR_ENTRYID = 32;
    GetMailInfos_DateRange = 64;
    GetMailInfos_OrderByDateTime = 128;

function RequestAccessToken(requestData: WideString): WideString;
var
    httpRequest: TServerXMLHTTP;
    oauthParser: TOAuthResponseParser;
    fullRequest: OleVariant;
    status: integer;
    responseText: WideString;
    accessToken: WideString;
    tokenUri, tenant_id: WideString;
begin
    result := '';

    httpRequest := TServerXMLHTTP.Create(nil);

    fullRequest :=  requestData;

    // If your application is not created by Office365 administrator,
    // please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
    // Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
    tenant_id := '79a42c6f-5a9a-439b-a2ca-7aa1b0ed9776';
    tokenUri := 'https://login.microsoftonline.com/' + tenant_id + '/oauth2/v2.0/token';

    httpRequest.setOption(2, 13056);
    httpRequest.open('POST', tokenUri, true);
    httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    httpRequest.send(fullRequest);

    while( httpRequest.readyState <> 4 ) do
    begin
        try
            httpRequest.waitForResponse(1);
        except
            writeln('Server response timeout (access token).');
            exit;
        end;
    end;

    status := httpRequest.status;
    responseText := httpRequest.responseText;

    if (status < 200) or (status >= 300) then
    begin
        writeln('Failed to get access token from server.' + responseText);
        exit;
    end;

    oauthParser := TOAuthResponseParser.Create(nil);
    oauthParser.Load(responseText);

    accessToken := oauthParser.AccessToken;

    if accessToken = '' then
    begin
        writeln('Failed to parse access token from server response.');
        exit;
    end;

    result := accessToken;
end;

function GenerateRequestData(): WideString;
const
    client_id: WideString = '8f54719b-4070-41ae-91ad-f48e3c793c5f';
    client_secret: WideString = 'cbmYyGQjz[d29wL2ArcgoO7HLwJXL/-.';
    scope: WideString = 'https://outlook.office365.com/.default';
begin
    result := 'client_id=' + client_id
            + '&client_secret=' + client_secret
            + '&scope=' + scope
            + '&grant_type=client_credentials';
end;

procedure RetrieveEmail();
var
    accessToken: WideString;
    Office365User: WideString;
    oServer: TMailServer;
    oClient: TMailClient;
    oTools: TTools;
    oMail: IMail;
    infos: IMailInfoCollection;
    oInfo: IMailInfo;
    localInbox, fileName: WideString;
    i: Integer;
begin

    try
        Office365User := 'user@mydomain.onmicrosoft.com';

        accessToken := RequestAccessToken(GenerateRequestData());
        if accessToken = '' then
        exit;

        // set current thread code page to system default code page.
        SetThreadLocale(GetSystemDefaultLCID());
        oTools := TTools.Create(nil);

        // Create a folder named "inbox" under
        // current directory to store the email files
        localInbox := GetCurrentDir() + '\inbox';
        oTools.CreateFolder(localInbox);

        oServer := TMailServer.Create(nil);
        // Office 365 Server
        oServer.Server := 'outlook.office365.com';
        // Use OAUTH 2.0
        oServer.AuthType := MailServerAuthXOAUTH2;

        oServer.User := Office365User;
        // Use access token as password
        oServer.Password := accessToken;
        // Use EWS Protocol
        oServer.Protocol := MailServerEWS;

        // Enable SSL Connection
        oServer.SSLConnection := true;


        oClient := TMailClient.Create(nil);
        oClient.LicenseCode := 'TryIt';

        writeln('Connecting ' + oServer.Server + ' ...');
        oClient.Connect1(oServer.DefaultInterface);
        writeln('Connected!');

        // Get new email only, if you want to get all emails, please remove this line
        oClient.GetMailInfosParam.GetMailInfosOptions := GetMailInfos_NewOnly;

        infos := oClient.GetMailInfoList();
        writeln(Format('Total %d email(s)', [infos.Count]));

        for i := 0 to infos.Count - 1 do
        begin
            oInfo := infos.Item[i];

            writeln(Format('Index: %d; Size: %d; UIDL: ' + oInfo.UIDL,
            [oInfo.Index, oInfo.Size]));

            // Generate a random file name by current local datetime,
            // You can use your method to generate the filename if you do not like it
            fileName := localInbox + '\' + oTools.GenFileName(i) + '.eml';

            // Receive email from IMAP server
            oMail := oClient.GetMail(oInfo);

            writeln('From: ' + oMail.From.Address + #13#10 +
                'Subject: ' + oMail.Subject);

            // Save email to local disk
            oMail.SaveAs(fileName, true);

            // Mark email as read to prevent retrieving this email again.
            oClient.MarkAsRead(oInfo, true);

            // If you want to delete current email, please use Delete method instead of MarkAsRead
            // oClient.Delete(oInfo);
        end;

        // Quit and expunge emails marked as deleted from IMAP server
        oClient.Quit;
    except
        on ep:Exception do
        writeln('Error: ' + ep.Message);
    end;

end;

begin

    CoInitialize(nil);

    writeln('+------------------------------------------------------------------+');
    writeln('  Sign in with MS OAuth');
    writeln('   If you got "This app is not verified" information in Web Browser, ');
    writeln('      click "Advanced" -> Go to ... to continue test.');
    writeln('+------------------------------------------------------------------+');
    writeln('');

    writeln('Press ENTER key to sign in...');
    readln;

    RetrieveEmail();

    writeln('Press ENTER key to quit...');
    readln;

end.