I'm trying to send an e-mail using Google App Engine. I'm getting the exception below and I'm not sure why at the moment. Any ideas?

javax.mail.SendFailedException: Send failure (javax.mail.MessagingException: Illegal Arguments (java.lang.IllegalArgumentException: Bad Request: Invalid sender format))
    at javax.mail.Transport.send(Transport.java:163)
    at javax.mail.Transport.send(Transport.java:48)
    at com.mystuff.service.mail.MailService.sendActivationEmail(MailService.java:145)

Below is the code related to sending the e-mail.

public final void sendActivationEmail(final UserAccount user) {
    final Properties props = new Properties();
    final Session session = Session.getDefaultInstance(props, null);
    final Message message = new MimeMessage(session);
    final Multipart multipart = new MimeMultipart();
    final MimeBodyPart htmlPart = new MimeBodyPart();
    final MimeBodyPart textPart = new MimeBodyPart();
    final Locale locale = LocaleContextHolder.getLocale();

    try {
        message.setFrom(new InternetAddress(getFromAddress(), "Qoogeo"));

        message.addRecipient(Message.RecipientType.TO,
            new InternetAddress(user.getUsername(),
                user.getFirstName() + " " + user.getLastName()));

        message.setSubject(messageSource.getMessage("mail.subject", null,
            locale));

        textPart.setContent(messageSource.getMessage("mail.body.txt",
            new Object[] {getHostname(), user.getActivationKey()}, locale),
            "text/plain");

        htmlPart.setContent(messageSource.getMessage("mail.body.html",
            new Object[] {getHostname(), user.getActivationKey()}, locale),
            "text/html");

        multipart.addBodyPart(textPart);
        multipart.addBodyPart(htmlPart);
        message.setContent(multipart);

        Transport.send(message);
    } catch (MessagingException e) {
        LOGGER.warn(ERROR_MSG, e);
    } catch (UnsupportedEncodingException e) {
        LOGGER.warn(ERROR_MSG, e);
    }
}

Also, getFromAddress() returns "[email protected]".