Send Attachments/files in Mail Java

The JavaMail FAQ can be found at the official java site here:
http://java.sun.com/products/javamail/FAQ.html
Q: How do I send a message with an attachment?
A: A message with attachments is represented as a MIME multipart message where the first part is the main body of the message and the other parts are the attachments. There are numerous examples showing how to construct such a message in the demo programs included in the JavaMail download package. To attach a file use the attachFile method of MimeBodyPart.

Q: How do I read a message with an attachment and save the attachment?
A: As described above, a message with an attachment is represented in MIME as a multipart message. In the simple case, the results of the Message object's getContent method will be a MimeMultipart object. The first body part of the multipart object wil be the main text of the message. The other body parts will be attachments. The msgshow.java demo program shows how to traverse all the multipart objects in a message and extract the data of each of the body parts. The getDisposition method will give you a hint as to whether the body part should be displayed inline or should be considered an attachment (but note that not all mailers provide this information). So to save the contents of a body part in a file, use the saveFile method of MimeBodyPart.

MimeMultipart messageContent = new MimeMultipart();

BodyPart bodyPart = new MimeBodyPart();
DataSource source = new FileDataSource(yourFile);
bodyPart.setDataHandler(new DataHandler(source);
bodyPart.setFileName("MyFile.ext");
bodyPart.setDisposition(Part.ATTACHMENT);

// Then add to your message:
messageContent.addBodyPart(bodyPart);