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Java

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

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

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Chilkat2 Java
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Email;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.MailMan;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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"
        //     }
        //
        JsonObject json = new JsonObject();
        try {
            json.loadFile("qa_data/tokens/_gmailSmtp.json");
        } catch (ChilkatException e) {
            System.out.println("Failed to load GMail access token file.");
            return;
        }

        String accessToken = json.stringOf("access_token");

        MailMan mailman = new MailMan();

        // Set the properties for the GMail SMTP server:
        mailman.setSmtpHost("smtp.gmail.com");
        mailman.setSmtpPort(587);
        mailman.setStartTLS(true);

        // The SMTP username should be the GMail address of the user's account that authorized your app to send email.
        mailman.setSmtpUsername("chilkat.support@gmail.com");
        mailman.setOAuth2AccessToken(accessToken);

        // Create a new email object
        Email email = new Email();

        email.setSubject("This is a test");
        email.setBody("This is a test");
        email.setFrom("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.
        try {
            mailman.sendEmail(email);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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).
        try {
            mailman.closeSmtpConnection();
        } catch (ChilkatException e) {
            System.out.println("Connection to SMTP server not closed cleanly.");
        }

        System.out.println("Email Sent via GMail with OAuth2 authentication.");
    }
}