sending email with attachment
import org.springframework.core.io.ClassPathResource;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
void sendEmailWithAttachment() throws MessagingException, IOException {
MimeMessage msg = javaMailSender.createMimeMessage();
// true = multipart message
MimeMessageHelper helper = new MimeMessageHelper(msg, true);
helper.setTo("to_@email");
helper.setSubject("Testing from Spring Boot");
// default = text/plain
//helper.setText("Check attachment for image!");
// true = text/html
helper.setText("<h1>Check attachment for image!</h1>", true);
// hard coded a file path
//FileSystemResource file = new FileSystemResource(new File("path/android.png"));
helper.addAttachment("my_photo.png", new ClassPathResource("android.png"));
javaMailSender.send(msg);
}