Unicode chars and Spring JavaMailSenderImpl, no unicode chars under Linux!

I'm using Spring and JavaMailSenderImpl, a famous spring class to send emails. My emails contain a lot of unicode chars like èéàò or most notably the dreaded € symbol. My classes work fine when the run on windows. The emails sent are with all the chars (plain text, no html). If I install my app on a Linux virtual server, I'll get all ? instead of the special chars. Is it Spring, Java configuration or something else?

Update

Basically the architecture is this: there is a Spring Web Application and I use spring JavaMailSenderImpl to get the work done. This is the configuration in servlet-context:

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="host" value="${email.server}" />
    <property name="username" value="${email.server_user}"></property>
    <property name="password" value="${email.server_pass}"></property>
</bean>

I'm using the same host on windows and linux to send mail (that is not the same machine where the application runs on... It is just a standard mail service provider over SMTP).

The code I use to send the email is simply:

SimpleMailMessage msg = new SimpleMailMessage();
            msg.setTo(adminEmail);
            msg.setFrom(adminEmail);
            msg.setSubject(subject);
            msg.setText(message);
            mailSender.send(msg);

Even setting:

System.setProperty("mail.mime.charset", "utf8");

at application startup doesn't solve the situation. In fact, before I was getting ? instead of €, now I get �...

Solution

I am posting the solution.

First make sure about the encoding of the source code (if there is inline text). In eclipse is the first screen if you choose project properties. Warning: if you change it later it will garble your text.

Second It is better to use MimeMailMessage so that you can specify the encoding, like this:

MimeMessage msg = mailSender.createMimeMessage();

        msg.addRecipient(RecipientType.TO, new InternetAddress(adminEmail));
        msg.addFrom(new InternetAddress[] { new InternetAddress(adminEmail) });

        msg.setSubject(subject, "UTF-8");
        msg.setText(message, "UTF-8");  
        mailSender.send(msg);

Third make sure the system property mail.mime.charset is set to UTF-8, either from Java command or by code like this:

System.setProperty("mail.mime.charset", "utf8");

Thanks to everybody that helped me sorting this out.