(MFC) GMail SMTP Send using Previously Obtained OAuth2 Access Token

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>
#include <CkMailMan.h>
#include <CkEmail.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    // See Get GMail SMTP Access Token 
    // for sample code showing how to obtain a GMail SMTP access token for desktop apps.

    // In this example, our access token was previously saved to the following file which contains JSON like this:
    // 	{
    // 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
    // 	 "token_type": "Bearer",
    // 	 "expires_in": 3600,
    // 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
    // 	}
    // 
    CkJsonObject json;
    bool success = json.LoadFile("qa_data/tokens/_gmailSmtp.json");
    if (success != true) {
        strOut.append("Failed to load GMail access token file.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    const char *accessToken = json.stringOf("access_token");

    CkMailMan mailman;

    // Set the properties for the GMail SMTP server:
    mailman.put_SmtpHost("smtp.gmail.com");
    mailman.put_SmtpPort(587);
    mailman.put_StartTLS(true);

    // The SMTP username should be the GMail address of the user's account that authorized your app to send email.
    mailman.put_SmtpUsername("chilkat.support@gmail.com");
    mailman.put_OAuth2AccessToken(accessToken);

    // Create a new email object
    CkEmail email;

    email.put_Subject("This is a test");
    email.put_Body("This is a test");
    email.put_From("Chilkat <chilkat.support@gmail.com>");
    email.AddTo("Chilkat Admin","admin@chilkatsoft.com");
    // To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    // Call SendEmail to connect to the SMTP server and send.
    // The connection (i.e. session) to the SMTP server remains
    // open so that subsequent SendEmail calls may use the
    // same connection.  
    success = mailman.SendEmail(email);
    if (success != true) {
        strOut.append(mailman.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // You may close the connection here.  If the connection is kept open, 
    // the next call to mailman.SendEmail will continue using the already-established connection
    // (and automatically re-connect if needed).
    success = mailman.CloseSmtpConnection();
    if (success != true) {
        strOut.append("Connection to SMTP server not closed cleanly.");
        strOut.append("\r\n");
    }

    strOut.append("Email Sent via GMail with OAuth2 authentication.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }