我有用户注册系统，之前正在向注册用户发送激活邮件，但现在系统没有向注册用户发送激活邮件：
<?php
/*~ class.phpmailer.php
/**
* PHPMailer - PHP email transport class
* @package PHPMailer
* @author Andy Prevost
* @copyright 2004 - 2009 Andy Prevost
*/
class PHPMailer {
/**
* Email priority (1 = High, 3 = Normal, 5 = low).
* @var int
*/
var $Priority = 3;
/**
* Sets the CharSet of the message.
* @var string
*/
var $CharSet = 'iso-8859-1';
/**
* Sets the Content-type of the message.
* @var string
*/
var $ContentType = 'text/plain';
/**
* Sets the Encoding of the message. Options for this are "8bit",
* "7bit", "binary", "base64", and "quoted-printable".
* @var string
*/
var $Encoding = '8bit';
/**
* Holds the most recent mailer error message.
* @var string
*/
var $ErrorInfo = '';
/**
* Sets the From email address for the message.
* @var string
*/
var $From = 'root@localhost';
/**
* Sets the From name of the message.
* @var string
*/
var $FromName = ' Webmaster,assamesesongs.org';
/**
* Sets the Sender email (Return-Path) of the message. If not empty,
* will be sent via -f to sendmail or as 'MAIL FROM' in smtp mode.
* @var string
*/
var $Sender = '';
/**
* Sets the Subject of the message.
* @var string
*/
var $Subject = '';
/**
* Sets the Body of the message. This can be either an HTML or text body.
* If HTML then run IsHTML(true).
* @var string
*/
var $Body = '';
/**
* Sets the text-only body of the message. This automatically sets the
* email to multipart/alternative. This body can be read by mail
* clients that do not have HTML email capability such as mutt. Clients
* that can read HTML will view the normal Body.
* @var string
*/
var $AltBody = '';
/**
* Sets word wrapping on the body of the message to a given number of
* characters.
* @var int
*/
var $WordWrap = 0;
/**
* Method to send mail: ("mail", "sendmail", or "smtp").
* @var string
*/
var $Mailer = 'mail';
/**
* Sets the path of the sendmail program.
* @var string
*/
var $Sendmail = '/usr/sbin/sendmail';
/**
* Path to PHPMailer plugins. This is now only useful if the SMTP class
* is in a different directory than the PHP include path.
* @var string
*/
var $PluginDir = '';
/**
* Holds PHPMailer version.
* @var string
*/
var $Version = "2.0.4";
/**
* Sets the email address that a reading confirmation will be sent.
* @var string
*/
var $ConfirmReadingTo = '';
/**
* Sets the hostname to use in Message-Id and Received headers
* and as default HELO string. If empty, the value returned
* by SERVER_NAME is used or 'localhost.localdomain'.
* @var string
*/
var $Hostname = '';
/**
* Sets the message ID to be used in the Message-Id header.
* If empty, a unique id will be generated.
* @var string
*/
var $MessageID = '';
}