title: "No MimeMessage content" exception when sending SimpleMailMessage
body: <p>I'm trying to send a very simple email with org.springframework.mail.javamail.JavaMailSenderImpl. Below is the code : </p>
  
  <pre><code>SimpleMailMessage mailMessage = new SimpleMailMessage();
  mailMessage.setTo(request.getCustomerEmail());
  mailMessage.setSubject("someSubject");
  mailMessage.setFrom("vincent@myDomain.com");
  mailSender.send(mailMessage);
  </code></pre>
  
  <p>This is the exception I get :</p>
  
  <pre><code>Caused by: org.springframework.mail.MailSendException: Failed messages: javax.mail.MessagingException: No MimeMessage content
  at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:459)
  at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:307)
  at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:296)
  </code></pre>
  
  <p>I really don't understand why this happens..</p>
  
  <p>Any idea ? </p>