public static EmailService getInstance() {
        return instance;
    }
A service to send email.<p>

This class has a few factory methods you can use to return message objects
or to add messages into a queue to be sent. Using these methods, you can
send emails in the following couple of ways:
<pre>
  EmailService.sendMessage(
    "Joe Bloe", "jbloe@place.org",
    "Jane Doe", "jane@doe.com",
    "Hello...",
    "This is the body of the email...",
    null
  );
</pre>
or
<pre>
  Message message = EmailService.createMimeMessage();
  // call setters on the message object
  // .
  // .
  // .
  emailService.sendMessage(message);
</pre><p>

This class is configured with a set of Jive properties:<ul>
     <li>{@code mail.smtp.host} -- the host name of your mail server, i.e.
         mail.yourhost.com. The default value is "localhost".
     <li>{@code mail.smtp.port} -- an optional property to change the smtp
         port used from the default of 25.
     <li>{@code mail.smtp.username} -- an optional property to change the
         username used to connect to the smtp server. Default is no username.
     <li>{@code mail.smtp.password} -- an optional property to change the
         password used to connect to the smtp server. Default is no password.
     <li>{@code mail.smtp.ssl} -- an optional property to set whether to use
         SSL to connect to the smtp server or not. Default is false.
     <li>{@code mail.debugEnabled} -- true if debug information should written out.
         Default is false.
</ul>
xmppserver/src/main/java/org/jivesoftware/util/EmailService.java