Sending attachments with emails in Javamail

Question

I'm trying to send attachments with emails using Javamail. Following is the code through which I'm trying to achieve that. It works as expected on a JRE1.6 environment. But on JRE1.5, the content of the file gets added to the mail body as text.I want the file to be sent as an attachment.
Any pointers on the observed difference in behavior would be highly appreciated!
String msgText = mailInfo.getMessage();
        String attachmentFileName = mailInfo.getFileName();
        MimeBodyPart mimeBodyPart = new MimeBodyPart();
        mimeBodyPart.setText(msgText);
        // create the second message part
        MimeBodyPart attachmentBodyPart = new MimeBodyPart();
        // attach the file to the message
        FileDataSource fileDataSource = new FileDataSource(attachmentFileName);
        attachmentBodyPart.setFileName(fileDataSource.getName());
        attachmentBodyPart.setDataHandler(new DataHandler(fileDataSource));
        // create the Multipart and add its parts to it
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(mimeBodyPart);
        multipart.addBodyPart(attachmentBodyPart);
        message.setContent(multipart);The email in case of JRE1.5 is as follows
{color:#0000ff}------=_Part_0_33189144.1233078680250
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Hi...Test Mail
------=_Part_0_33189144.1233078680250
Content-Type: application/octet-stream; name=corba_architecture.pdf
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=corba_architecture.pdf
Content-ID: Attachment
JVBERi0xLjIgDSXi48/TDQogDTggMCBvYmoNPDwNL0xlbmd0aCA5IDAgUg0vRmlsdGVyIC9GbGF0
ZURlY29kZSANPj4Nc3RyZWFtDQpIiUWPW07DMBBFV+A93E9QlWBP/Kj5awt8USFRbyBKnTQIkshK
YfvYcQoaybrSzDkzFhCxQgemeWkUyKTXEIeSHMGjZXvHSFBJCpXUpQLcE+NIlbCHFw4pUxeuZQUv
ueY25gYxk9mKmH9wtwvNpZ99M1+jc2wxXzxweHvf73AP9xGFhaIsTyC3/w6ZDYfxaxoHP8w4jmf/
------=_Part_0_33189144.1233078680250-- {color}

Answer 1

Following is the debug trace obtained on running the program on 1.5.
+12:45:57,218 INFO [MailerThread] EmailManager:306 - Sending message {toAddress [email protected],+
+replyTo =null,+
+cc =null,+
+message =Hi...Test Mail,+
+subject =test mail,+
+contentType =null fileName =C:\docs\cbe\dist computing\A.txt }+
Loading javamail.default.providers from jar:file:/C:/docs/cbe/lib/mail-1.4.jar!/META-INF/javamail.default.providers
DEBUG: loading new provider protocol=imap, className=com.sun.mail.imap.IMAPStore, vendor=Sun Microsystems, Inc, version=null
DEBUG: loading new provider protocol=imaps, className=com.sun.mail.imap.IMAPSSLStore, vendor=Sun Microsystems, Inc, version=null
DEBUG: loading new provider protocol=smtp, className=com.sun.mail.smtp.SMTPTransport, vendor=Sun Microsystems, Inc, version=null
DEBUG: loading new provider protocol=smtps, className=com.sun.mail.smtp.SMTPSSLTransport, vendor=Sun Microsystems, Inc, version=null
DEBUG: loading new provider protocol=pop3, className=com.sun.mail.pop3.POP3Store, vendor=Sun Microsystems, Inc, version=null
DEBUG: loading new provider protocol=pop3s, className=com.sun.mail.pop3.POP3SSLStore, vendor=Sun Microsystems, Inc, version=null
DEBUG: getProvider() returning provider protocol=smtp; type=javax.mail.Provider$Type@77eaf8; class=com.sun.mail.smtp.SMTPTransport; vendor=Sun Microsystems, Inc
DEBUG SMTP: useEhlo true, useAuth false
DEBUG SMTP: trying to connect to host "10.16.68.131", port 25, isSSL false
+220 mailhost5.vmware.com ESMTP Postfix (mailhost5)+
DEBUG SMTP: connected to host "10.16.68.131", port: 25
EHLO sbanerjee
+250-mailhost5.vmware.com+
+250-PIPELINING+
+250-SIZE 26800000+
+250-VRFY+
+250-ETRN+
+250-ENHANCEDSTATUSCODES+
+250-8BITMIME+
+250 DSN+
DEBUG SMTP: Found extension "PIPELINING", arg ""
DEBUG SMTP: Found extension "SIZE", arg "26800000"
DEBUG SMTP: Found extension "VRFY", arg ""
DEBUG SMTP: Found extension "ETRN", arg ""
DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
DEBUG SMTP: Found extension "8BITMIME", arg ""
DEBUG SMTP: Found extension "DSN", arg ""
DEBUG SMTP: use8bit false
MAIL FROM:<[email protected]>
+250 2.1.0 Ok+
RCPT TO:<[email protected]>
+250 2.1.5 Ok+
DEBUG SMTP: Verified Addresses
DEBUG SMTP:   [email protected]
DATA
+354 End data with <CR><LF>.<CR><LF>+
------=_Part_0_3278348.1233126957281
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Hi...Test Mail
------=_Part_0_3278348.1233126957281
Content-Type: text/plain; charset=us-ascii; name=A.txt
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename=A.txt
Content-ID: Attachment
adasdasdd
------=_Part_0_3278348.1233126957281--
+.+
+250 2.0.0 Ok: queued as 5BE5BDC100+
+12:45:59,125 INFO [MailerThread] EmailManager:331 - Message {toAddress [email protected],+
+replyTo =null,+
+cc =null,+
+message =Hi...Test Mail,+
+subject =test mail,+
+contentType =null fileName =C:\docs\cbe\dist computing\A.txt } sent to the SMTP server successfully+