In what jar is: com.sun.activation.registries.MailCapFile located?

Question

I am attempting to implement JavaMail in an application in an OS400 environment. I simply want to send a text message (no attachements). My code works up to the point of: Transport.send(message); where I get a NoClassDefFound: com/sun/activation/registries/MailCapFile
Here's the code:
private void sendEmail(String recipient,String msg){
     String smtpSvr = "xxx.yyyyyyyyy.com";     
     String subject = "Log Transfer Errors";
     String from = "[email protected]";
     Properties p = System.getProperties();
     p.put("mail.smtp.host",smtpSvr);
     Session mailSession = Session.getDefaultInstance(p,null);
     Message message = new MimeMessage(mailSession);
     try {
     message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(recipient));
     message.setFrom(new InternetAddress(from));
     message.setSubject(subject);
     message.setContent(msg,"text/plain");
     Transport.send(message);
     } catch (AddressException e) {
          System.out.println(""+e);
     } catch (MessagingException e) {
          System.out.println(""+e);
     } catch (Exception e) {
          System.out.println(""+e);
I have JavaMail working fine in a servlet running in WebSphere 5.0 on the same OS400 v5r2.
Do I need to add another jar file to my CLASSPATH?? Don't know in what jar the:
com.sun.activation.registries.MailCapFile class is in????

Answer 1

From its name I would guess that it's in "activation.jar". In fact looking in that file on my AS/400, it IS in activation.jar. You must have missed the instructions that you would need that for JavaMail to work properly. You can get it here:
http://java.sun.com/products/javabeans/glasgow/jaf.html