使用Javax邮件发送没有附件的Android邮件

Question

我尝试使用javax邮件发送电子邮件，但我在网上找到的所有资源都带有附件，因此我的代码会抛出错误：

public boolean send() throws Exception {
        Properties props = _setProperties();

        if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) {
            Session session = Session.getInstance(props, this);

            MimeMessage msg = new MimeMessage(session);

            msg.setFrom(new InternetAddress(_from));

            InternetAddress[] addressTo = new InternetAddress[_to.length];
            for (int i = 0; i < _to.length; i++) {
                addressTo[i] = new InternetAddress(_to[i]);
            }
            msg.setRecipients(MimeMessage.RecipientType.TO, addressTo);

            msg.setSubject(_subject);
            msg.setSentDate(new Date());

            // setup message body
            BodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setText(_body);
            _multipart.addBodyPart(messageBodyPart);

            // Put parts in message
            msg.setContent(_multipart);
            final  MimeMessage msg2 = msg;
            // send email
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        Transport.send(msg2);
                    } catch (MessagingException e) {
                        e.printStackTrace();
                    }
                }
            }).start();

            return true;
        } else {
            return false;
        }
    }

最终投掷：

W/System.err: javax.mail.MessagingException: IOException while sending message;
W/System.err:   nested exception is:
W/System.err:   java.io.FileNotFoundException: /sdcard/filelocation (No such file or directory)
W/System.err:     at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:676)
W/System.err:     at javax.mail.Transport.send0(Transport.java:189)
W/System.err:     at javax.mail.Transport.send(Transport.java:118)
W/System.err:     at com.example..logintest.Mail$1$override.run(Mail.java:143)
W/System.err:     at com.example..logintest.Mail$1$override.access$dispatch(Mail.java)
W/System.err:     at com.example..logintest.Mail$1.run(Mail.java:0)
W/System.err:     at java.lang.Thread.run(Thread.java:761)
W/System.err: Caused by: java.io.FileNotFoundException: /sdcard/filelocation (No such file or directory)

我无法在网上找到任何帮助，我绝对不会尝试发送文件。我的_body只是一个简单的字符串。有任何想法吗？我不明白如何设置字段，以便他们不会尝试发送附件。