Create the message you want to send.

Specify the following content in the message:

• From header field
• When an argument is not specified, the return value of the getLocalAddress method of the InternetAddress class is set for the From header field. When you use a mail configuration, the value of the From header field set in the mail configuration is set in the message.
• To header field
  You can set the CC or BCC header field by specifying MimeMessage.RecipientType.CC or MimeMessage.RecipientType.BCC instead of MimeMessage.RecipientType.TO.
  
• Subject header field
  When you do not specify the charset parameter, the value of the mail.mime.charset property is used in encoding.
  
• User-defined field
• Mail body
  Set the mail body as the content type text or plain in the mail contents. Furthermore, if the charset parameter is not specified, the value of the mail.mime.charset property is used in encoding.
  
• Date header field

An example of setting the message contents is as follows:

MimeMessage msg = new MimeMessage(session);
try{
    // Set up the From header field
    msg.setFrom();
 
    // Set up the To header field
    msg.setRecipients(MimeMessage.RecipientType.TO, "to_address@example.com");
 
    // Set up the Subject header field
    msg.setSubject("Message subject", "ISO-2022-JP");
 
    //Set up the user-defined field
    msg.setHeader("MyHeader", "MySendMailClient");
 
    // Set up the mail text
    msg.setText("Mail message text", "ISO-2022-JP");
 
    // Set up the Date header field
    msg.setSentDate(new java.util.Date());
 
} catch (MessagingException e) {
    // Failed to analyze mail address
}