How to send UTF-8 encoded email body with JavaMailSenderImpl?

Question

I am sending an email this way:

@Test
public void testEmailCharacterSet() throws MessagingException, UnsupportedEncodingException {
    JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
    mailSender.setDefaultEncoding("utf-8");
    mailSender.setHost("*****");
    mailSender.setUsername("*****");
    mailSender.setPassword("*****");

    Properties properties = new Properties();
    properties.setProperty("mail.mime.charset", "utf-8");

    mailSender.setJavaMailProperties(properties);

    MimeMessage mimeMessage = mailSender.createMimeMessage();
    MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, false, "utf-8");
    mimeMessage.setContent("Árvíztűrő tükörfúrógép 3", "text/html"); 
    helper.setFrom("[email protected]");
    helper.setTo("[email protected]");

    mailSender.send(mimeMessage);
}

As you can see I am setting utf-8 everywhere when I can. My problem is that the outgoing raw bytes are still in Latin1, at least this is what I see in Wireshark:

Date: Sun, 17 May 2015 18:16:21 +0200 (CEST)
From: [email protected]
To: [email protected]
Message-ID: <13648335.0.1431879381653.JavaMail.foo@foo-dell>
MIME-Version: 1.0
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

=C1rv=EDzt?r? t=FCk=F6rf=FAr=F3g=E9p 3
.

So basically the headers are saying UTF-8, but the outgoing bytes already contain question mark where ő and ű should appear, which are two characters that are missing from Latin1. The JVM's file.encoding is not UTF-8, but I am looking for a way to keep that as it is and solve this problem only in the emailing side.

Thanks!

Update

I have previously successfully used the plain old method to send email, and it's interesting that that still works:

Message mimeMessage = new MimeMessage(session);
mimeMessage.setContent("Árvíztűrő tükörfúrógép 7 oldschool", "text/html; charset=utf-8"); 

So it's clearly something specific to the JavaMailSenderImpl only.

Answer 1

If you add this lines:

properties.setProperty("mail.smtp.allow8bitmime", "true");
properties.setProperty("mail.smtps.allow8bitmime", "true");

to your code, message will have Content-Transfer-Encoding: header set to 8bit and mail will be readable.

Answer 2

This works for me - link

mailSender.send(new MimeMessagePreparator() {
   public void prepare(MimeMessage mimeMessage) throws MessagingException {
     MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");
     message.setFrom("[email protected]");
     message.setTo("[email protected]");
     message.setSubject("my subject");
     message.setText("my text <img src='cid:myLogo'>", true);
     message.addInline("myLogo", new ClassPathResource("img/mylogo.gif"));
     message.addAttachment("myDocument.pdf", new ClassPathResource("doc/myDocument.pdf"));
   }
 });