/**
 * Send an email to a specified user
 *
 * @param stdClass $user  A {@link $USER} object
 * @param stdClass $from A {@link $USER} object
 * @param string $subject plain text subject line of the email
 * @param string $messagetext plain text version of the message
 * @param string $messagehtml complete html version of the message (optional)
 * @param string $attachment a file on the filesystem, either relative to $CFG->dataroot or a full path to a file in $CFG->tempdir
 * @param string $attachname the name of the file (extension indicates MIME)
 * @param bool $usetrueaddress determines whether $from email address should
 *          be sent out. Will be overruled by user profile setting for maildisplay
 * @param string $replyto Email address to reply to
 * @param string $replytoname Name of reply to recipient
 * @param int $wordwrapwidth custom word wrap width, default 79
 * @return bool Returns true if mail was sent OK and false if there was an error.
 */
function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '', $attachment = '', $attachname = '', $usetrueaddress = true, $replyto = '', $replytoname = '', $wordwrapwidth = 79)
{
    global $CFG;
    if (empty($user) or empty($user->id)) {
        debugging('Can not send email to null user', DEBUG_DEVELOPER);
        return false;
    }
    if (empty($user->email)) {
        debugging('Can not send email to user without email: ' . $user->id, DEBUG_DEVELOPER);
        return false;
    }
    if (!empty($user->deleted)) {
        debugging('Can not send email to deleted user: ' . $user->id, DEBUG_DEVELOPER);
        return false;
    }
    if (defined('BEHAT_SITE_RUNNING')) {
        // Fake email sending in behat.
        return true;
    }
    if (!empty($CFG->noemailever)) {
        // Hidden setting for development sites, set in config.php if needed.
        debugging('Not sending email due to $CFG->noemailever config setting', DEBUG_NORMAL);
        return true;
    }
    if (!empty($CFG->divertallemailsto)) {
        $subject = "[DIVERTED {$user->email}] {$subject}";
        $user = clone $user;
        $user->email = $CFG->divertallemailsto;
    }
    // Skip mail to suspended users.
    if (isset($user->auth) && $user->auth == 'nologin' or isset($user->suspended) && $user->suspended) {
        return true;
    }
    if (!validate_email($user->email)) {
        // We can not send emails to invalid addresses - it might create security issue or confuse the mailer.
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") email ({$user->email}) is invalid! Not sending.");
        return false;
    }
    if (over_bounce_threshold($user)) {
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") is over bounce threshold! Not sending.");
        return false;
    }
    // TLD .invalid  is specifically reserved for invalid domain names.
    // For More information, see {@link http://tools.ietf.org/html/rfc2606#section-2}.
    if (substr($user->email, -8) == '.invalid') {
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") email domain ({$user->email}) is invalid! Not sending.");
        return true;
        // This is not an error.
    }
    // If the user is a remote mnet user, parse the email text for URL to the
    // wwwroot and modify the url to direct the user's browser to login at their
    // home site (identity provider - idp) before hitting the link itself.
    if (is_mnet_remote_user($user)) {
        require_once $CFG->dirroot . '/mnet/lib.php';
        $jumpurl = mnet_get_idp_jump_url($user);
        $callback = partial('mnet_sso_apply_indirection', $jumpurl);
        $messagetext = preg_replace_callback("%({$CFG->wwwroot}[^[:space:]]*)%", $callback, $messagetext);
        $messagehtml = preg_replace_callback("%href=[\"'`]({$CFG->wwwroot}[\\w_:\\?=#&@/;.~-]*)[\"'`]%", $callback, $messagehtml);
    }
    $mail = get_mailer();
    if (!empty($mail->SMTPDebug)) {
        echo '<pre>' . "\n";
    }
    $temprecipients = array();
    $tempreplyto = array();
    $supportuser = core_user::get_support_user();
    // Make up an email address for handling bounces.
    if (!empty($CFG->handlebounces)) {
        $modargs = 'B' . base64_encode(pack('V', $user->id)) . substr(md5($user->email), 0, 16);
        $mail->Sender = generate_email_processing_address(0, $modargs);
    } else {
        $mail->Sender = $supportuser->email;
    }
    if (!empty($CFG->emailonlyfromnoreplyaddress)) {
        $usetrueaddress = false;
        if (empty($replyto) && $from->maildisplay) {
            $replyto = $from->email;
            $replytoname = fullname($from);
        }
    }
    if (is_string($from)) {
        // So we can pass whatever we want if there is need.
        $mail->From = $CFG->noreplyaddress;
//.........这里部分代码省略.........

/**
 * Send an email to a specified user
 *
 * @param stdClass $user  A {@link $USER} object
 * @param stdClass $from A {@link $USER} object
 * @param string $subject plain text subject line of the email
 * @param string $messagetext plain text version of the message
 * @param string $messagehtml complete html version of the message (optional)
 * @param string $attachment a file on the filesystem, either relative to $CFG->dataroot or a full path to a file in $CFG->tempdir
 * @param string $attachname the name of the file (extension indicates MIME)
 * @param bool $usetrueaddress determines whether $from email address should
 *          be sent out. Will be overruled by user profile setting for maildisplay
 * @param string $replyto Email address to reply to
 * @param string $replytoname Name of reply to recipient
 * @param int $wordwrapwidth custom word wrap width, default 79
 * @return bool Returns true if mail was sent OK and false if there was an error.
 */
function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '', $attachment = '', $attachname = '', $usetrueaddress = true, $replyto = '', $replytoname = '', $wordwrapwidth = 79)
{
    global $CFG, $PAGE, $SITE;
    if (empty($user) or empty($user->id)) {
        debugging('Can not send email to null user', DEBUG_DEVELOPER);
        return false;
    }
    if (empty($user->email)) {
        debugging('Can not send email to user without email: ' . $user->id, DEBUG_DEVELOPER);
        return false;
    }
    if (!empty($user->deleted)) {
        debugging('Can not send email to deleted user: ' . $user->id, DEBUG_DEVELOPER);
        return false;
    }
    if (defined('BEHAT_SITE_RUNNING')) {
        // Fake email sending in behat.
        return true;
    }
    if (!empty($CFG->noemailever)) {
        // Hidden setting for development sites, set in config.php if needed.
        debugging('Not sending email due to $CFG->noemailever config setting', DEBUG_NORMAL);
        return true;
    }
    if (email_should_be_diverted($user->email)) {
        $subject = "[DIVERTED {$user->email}] {$subject}";
        $user = clone $user;
        $user->email = $CFG->divertallemailsto;
    }
    // Skip mail to suspended users.
    if (isset($user->auth) && $user->auth == 'nologin' or isset($user->suspended) && $user->suspended) {
        return true;
    }
    if (!validate_email($user->email)) {
        // We can not send emails to invalid addresses - it might create security issue or confuse the mailer.
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") email ({$user->email}) is invalid! Not sending.");
        return false;
    }
    if (over_bounce_threshold($user)) {
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") is over bounce threshold! Not sending.");
        return false;
    }
    // TLD .invalid  is specifically reserved for invalid domain names.
    // For More information, see {@link http://tools.ietf.org/html/rfc2606#section-2}.
    if (substr($user->email, -8) == '.invalid') {
        debugging("email_to_user: User {$user->id} (" . fullname($user) . ") email domain ({$user->email}) is invalid! Not sending.");
        return true;
        // This is not an error.
    }
    // If the user is a remote mnet user, parse the email text for URL to the
    // wwwroot and modify the url to direct the user's browser to login at their
    // home site (identity provider - idp) before hitting the link itself.
    if (is_mnet_remote_user($user)) {
        require_once $CFG->dirroot . '/mnet/lib.php';
        $jumpurl = mnet_get_idp_jump_url($user);
        $callback = partial('mnet_sso_apply_indirection', $jumpurl);
        $messagetext = preg_replace_callback("%({$CFG->wwwroot}[^[:space:]]*)%", $callback, $messagetext);
        $messagehtml = preg_replace_callback("%href=[\"'`]({$CFG->wwwroot}[\\w_:\\?=#&@/;.~-]*)[\"'`]%", $callback, $messagehtml);
    }
    $mail = get_mailer();
    if (!empty($mail->SMTPDebug)) {
        echo '<pre>' . "\n";
    }
    $temprecipients = array();
    $tempreplyto = array();
    // Make sure that we fall back onto some reasonable no-reply address.
    $noreplyaddress = empty($CFG->noreplyaddress) ? 'noreply@' . get_host_from_url($CFG->wwwroot) : $CFG->noreplyaddress;
    // Make up an email address for handling bounces.
    if (!empty($CFG->handlebounces)) {
        $modargs = 'B' . base64_encode(pack('V', $user->id)) . substr(md5($user->email), 0, 16);
        $mail->Sender = generate_email_processing_address(0, $modargs);
    } else {
        $mail->Sender = $noreplyaddress;
    }
    $alloweddomains = null;
    if (!empty($CFG->allowedemaildomains)) {
        $alloweddomains = explode(PHP_EOL, $CFG->allowedemaildomains);
    }
    // Email will be sent using no reply address.
    if (empty($alloweddomains)) {
        $usetrueaddress = false;
    }
    if (is_string($from)) {
//.........这里部分代码省略.........

/** 
 * Always use this function for all emails to users
 * 
 * @param object $userto user object to send email to. must contain firstname,lastname,preferredname,email
 * @param object $userfrom user object to send email from. If null, email will come from mahara
 * @param string $subject email subject
 * @param string $messagetext text version of email
 * @param string $messagehtml html version of email (will send both html and text)
 * @param array  $customheaders email headers
 * @throws EmailException
 * @throws EmailDisabledException
 */
function email_user($userto, $userfrom, $subject, $messagetext, $messagehtml = '', $customheaders = null)
{
    global $IDPJUMPURL;
    static $mnetjumps = array();
    if (!get_config('sendemail')) {
        // You can entirely disable Mahara from sending any e-mail via the
        // 'sendemail' configuration variable
        return true;
    }
    if (empty($userto)) {
        throw new InvalidArgumentException("empty user given to email_user");
    }
    if (!($mailinfo = can_receive_email($userto))) {
        throw new EmailDisabledException("email for this user has been disabled");
    }
    // If the user is a remote xmlrpc user, trawl through the email text for URLs
    // to our wwwroot and modify the url to direct the user's browser to login at
    // their home site before hitting the link on this site
    if (!empty($userto->mnethostwwwroot) && !empty($userto->mnethostapp)) {
        require_once get_config('docroot') . 'auth/xmlrpc/lib.php';
        // Form the request url to hit the idp's jump.php
        if (isset($mnetjumps[$userto->mnethostwwwroot])) {
            $IDPJUMPURL = $mnetjumps[$userto->mnethostwwwroot];
        } else {
            $mnetjumps[$userto->mnethostwwwroot] = $IDPJUMPURL = PluginAuthXmlrpc::get_jump_url_prefix($userto->mnethostwwwroot, $userto->mnethostapp);
        }
        $wwwroot = get_config('wwwroot');
        $messagetext = preg_replace_callback('%(' . $wwwroot . '([\\w_:\\?=#&@/;.~-]*))%', 'localurl_to_jumpurl', $messagetext);
        $messagehtml = preg_replace_callback('%href=["\'`](' . $wwwroot . '([\\w_:\\?=#&@/;.~-]*))["\'`]%', 'localurl_to_jumpurl', $messagehtml);
    }
    require_once 'phpmailer/class.phpmailer.php';
    $mail = new phpmailer();
    // Leaving this commented out - there's no reason for people to know this
    //$mail->Version = 'Mahara ' . get_config('release');
    $mail->PluginDir = get_config('libroot') . 'phpmailer/';
    $mail->CharSet = 'UTF-8';
    $smtphosts = get_config('smtphosts');
    if ($smtphosts == 'qmail') {
        // use Qmail system
        $mail->IsQmail();
    } else {
        if (empty($smtphosts)) {
            // use PHP mail() = sendmail
            $mail->IsMail();
        } else {
            $mail->IsSMTP();
            // use SMTP directly
            $mail->Host = get_config('smtphosts');
            if (get_config('smtpuser')) {
                // Use SMTP authentication
                $mail->SMTPAuth = true;
                $mail->Username = get_config('smtpuser');
                $mail->Password = get_config('smtppass');
            }
        }
    }
    if (get_config('bounces_handle') && isset($mailinfo->owner)) {
        $mail->Sender = generate_email_processing_address($mailinfo->owner, $userto);
    }
    if (empty($userfrom) || $userfrom->email == get_config('noreplyaddress')) {
        if (empty($mail->Sender)) {
            $mail->Sender = get_config('noreplyaddress');
        }
        $mail->From = get_config('noreplyaddress');
        $mail->FromName = isset($userfrom->id) ? display_name($userfrom, $userto) : get_config('sitename');
        $customheaders[] = 'Precedence: Bulk';
        // Try to avoid pesky out of office responses
        $messagetext .= "\n\n" . get_string('pleasedonotreplytothismessage') . "\n";
        if ($messagehtml) {
            $messagehtml .= "\n\n<p>" . get_string('pleasedonotreplytothismessage') . "</p>\n";
        }
    } else {
        if (empty($mail->Sender)) {
            $mail->Sender = $userfrom->email;
        }
        $mail->From = $userfrom->email;
        $mail->FromName = display_name($userfrom, $userto);
    }
    $replytoset = false;
    if (!empty($customheaders) && is_array($customheaders)) {
        foreach ($customheaders as $customheader) {
            $mail->AddCustomHeader($customheader);
            if (0 === stripos($customheader, 'reply-to')) {
                $replytoset = true;
            }
        }
    }
    if (!$replytoset) {
//.........这里部分代码省略.........

/**
 * Send an email to a specified user
 *
 * @uses $CFG
 * @uses $FULLME
 * @uses $MNETIDPJUMPURL IdentityProvider(IDP) URL user hits to jump to mnet peer.
 * @uses SITEID
 * @param user $user  A {@link $USER} object
 * @param user $from A {@link $USER} object
 * @param string $subject plain text subject line of the email
 * @param string $messagetext plain text version of the message
 * @param string $messagehtml complete html version of the message (optional)
 * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
 * @param string $attachname the name of the file (extension indicates MIME)
 * @param bool $usetrueaddress determines whether $from email address should
 *          be sent out. Will be overruled by user profile setting for maildisplay
 * @param int $wordwrapwidth custom word wrap width
 * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
 *          was blocked by user and "false" if there was another sort of error.
 */
function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '', $attachment = '', $attachname = '', $usetrueaddress = true, $replyto = '', $replytoname = '', $wordwrapwidth = 79)
{
    global $CFG, $FULLME, $MNETIDPJUMPURL;
    static $mnetjumps = array();
    if (empty($user) || empty($user->email)) {
        return false;
    }
    if (!empty($user->deleted)) {
        // do not mail delted users
        return false;
    }
    if (!empty($CFG->noemailever)) {
        // hidden setting for development sites, set in config.php if needed
        return true;
    }
    // skip mail to suspended users
    if (isset($user->auth) && $user->auth == 'nologin') {
        return true;
    }
    if (!empty($user->emailstop)) {
        return 'emailstop';
    }
    if (over_bounce_threshold($user)) {
        error_log("User {$user->id} (" . fullname($user) . ") is over bounce threshold! Not sending.");
        return false;
    }
    // If the user is a remote mnet user, parse the email text for URL to the
    // wwwroot and modify the url to direct the user's browser to login at their
    // home site (identity provider - idp) before hitting the link itself
    if (is_mnet_remote_user($user)) {
        require_once $CFG->dirroot . '/mnet/lib.php';
        // Form the request url to hit the idp's jump.php
        if (isset($mnetjumps[$user->mnethostid])) {
            $MNETIDPJUMPURL = $mnetjumps[$user->mnethostid];
        } else {
            $idp = mnet_get_peer_host($user->mnethostid);
            $idpjumppath = '/auth/mnet/jump.php';
            $MNETIDPJUMPURL = $idp->wwwroot . $idpjumppath . '?hostwwwroot=' . $CFG->wwwroot . '&wantsurl=';
            $mnetjumps[$user->mnethostid] = $MNETIDPJUMPURL;
        }
        $messagetext = preg_replace_callback("%({$CFG->wwwroot}[^[:space:]]*)%", 'mnet_sso_apply_indirection', $messagetext);
        $messagehtml = preg_replace_callback("%href=[\"'`]({$CFG->wwwroot}[\\w_:\\?=#&@/;.~-]*)[\"'`]%", 'mnet_sso_apply_indirection', $messagehtml);
    }
    $mail =& get_mailer();
    if (!empty($mail->SMTPDebug)) {
        echo '<pre>' . "\n";
    }
    /// We are going to use textlib services here
    $textlib = textlib_get_instance();
    $supportuser = generate_email_supportuser();
    // make up an email address for handling bounces
    if (!empty($CFG->handlebounces)) {
        $modargs = 'B' . base64_encode(pack('V', $user->id)) . substr(md5($user->email), 0, 16);
        $mail->Sender = generate_email_processing_address(0, $modargs);
    } else {
        $mail->Sender = $supportuser->email;
    }
    if (is_string($from)) {
        // So we can pass whatever we want if there is need
        $mail->From = $CFG->noreplyaddress;
        $mail->FromName = $from;
    } else {
        if ($usetrueaddress and $from->maildisplay) {
            $mail->From = stripslashes($from->email);
            $mail->FromName = fullname($from);
        } else {
            $mail->From = $CFG->noreplyaddress;
            $mail->FromName = fullname($from);
            if (empty($replyto)) {
                $mail->AddReplyTo($CFG->noreplyaddress, get_string('noreplyname'));
            }
        }
    }
    if (!empty($replyto)) {
        $mail->AddReplyTo($replyto, $replytoname);
    }
    $mail->Subject = substr(stripslashes($subject), 0, 900);
    $mail->AddAddress(stripslashes($user->email), fullname($user));
    $mail->WordWrap = $wordwrapwidth;
    // set word wrap
//.........这里部分代码省略.........

/**
 * Send an email to a specified user
 *
 * @global object
 * @global string
 * @global string IdentityProvider(IDP) URL user hits to jump to mnet peer.
 * @uses SITEID
 * @param stdClass $user  A {@link $USER} object
 * @param stdClass $from A {@link $USER} object
 * @param string $subject plain text subject line of the email
 * @param string $messagetext plain text version of the message
 * @param string $messagehtml complete html version of the message (optional)
 * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
 * @param string $attachname the name of the file (extension indicates MIME)
 * @param bool $usetrueaddress determines whether $from email address should
 *          be sent out. Will be overruled by user profile setting for maildisplay
 * @param string $replyto Email address to reply to
 * @param string $replytoname Name of reply to recipient
 * @param int $wordwrapwidth custom word wrap width, default 79
 * @return bool Returns true if mail was sent OK and false if there was an error.
 */
function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '', $attachment = '', $attachname = '', $usetrueaddress = true, $replyto = '', $replytoname = '', $wordwrapwidth = 79)
{
    global $CFG, $FULLME;
    if (empty($user) || empty($user->email)) {
        mtrace('Error: lib/moodlelib.php email_to_user(): User is null or has no email');
        return false;
    }
    if (!empty($user->deleted)) {
        // do not mail delted users
        mtrace('Error: lib/moodlelib.php email_to_user(): User is deleted');
        return false;
    }
    if (!empty($CFG->noemailever)) {
        // hidden setting for development sites, set in config.php if needed
        mtrace('Error: lib/moodlelib.php email_to_user(): Not sending email due to noemailever config setting');
        return true;
    }
    if (!empty($CFG->divertallemailsto)) {
        $subject = "[DIVERTED {$user->email}] {$subject}";
        $user = clone $user;
        $user->email = $CFG->divertallemailsto;
    }
    // skip mail to suspended users
    if (isset($user->auth) && $user->auth == 'nologin') {
        return true;
    }
    if (over_bounce_threshold($user)) {
        $bouncemsg = "User {$user->id} (" . fullname($user) . ") is over bounce threshold! Not sending.";
        error_log($bouncemsg);
        mtrace('Error: lib/moodlelib.php email_to_user(): ' . $bouncemsg);
        return false;
    }
    // If the user is a remote mnet user, parse the email text for URL to the
    // wwwroot and modify the url to direct the user's browser to login at their
    // home site (identity provider - idp) before hitting the link itself
    if (is_mnet_remote_user($user)) {
        require_once $CFG->dirroot . '/mnet/lib.php';
        $jumpurl = mnet_get_idp_jump_url($user);
        $callback = partial('mnet_sso_apply_indirection', $jumpurl);
        $messagetext = preg_replace_callback("%({$CFG->wwwroot}[^[:space:]]*)%", $callback, $messagetext);
        $messagehtml = preg_replace_callback("%href=[\"'`]({$CFG->wwwroot}[\\w_:\\?=#&@/;.~-]*)[\"'`]%", $callback, $messagehtml);
    }
    $mail = get_mailer();
    if (!empty($mail->SMTPDebug)) {
        echo '<pre>' . "\n";
    }
    $temprecipients = array();
    $tempreplyto = array();
    $supportuser = generate_email_supportuser();
    // make up an email address for handling bounces
    if (!empty($CFG->handlebounces)) {
        $modargs = 'B' . base64_encode(pack('V', $user->id)) . substr(md5($user->email), 0, 16);
        $mail->Sender = generate_email_processing_address(0, $modargs);
    } else {
        $mail->Sender = $supportuser->email;
    }
    if (is_string($from)) {
        // So we can pass whatever we want if there is need
        $mail->From = $CFG->noreplyaddress;
        $mail->FromName = $from;
    } else {
        if ($usetrueaddress and $from->maildisplay) {
            $mail->From = $from->email;
            $mail->FromName = fullname($from);
        } else {
            $mail->From = $CFG->noreplyaddress;
            $mail->FromName = fullname($from);
            if (empty($replyto)) {
                $tempreplyto[] = array($CFG->noreplyaddress, get_string('noreplyname'));
            }
        }
    }
    if (!empty($replyto)) {
        $tempreplyto[] = array($replyto, $replytoname);
    }
    $mail->Subject = substr($subject, 0, 900);
    $temprecipients[] = array($user->email, fullname($user));
    $mail->WordWrap = $wordwrapwidth;
    // set word wrap
//.........这里部分代码省略.........

/**
 * Always use this function for all emails to users
 *
 * @param object $userto user object to send email to. must contain firstname,lastname,preferredname,email
 * @param object $userfrom user object to send email from. If null, email will come from mahara
 * @param string $subject email subject
 * @param string $messagetext text version of email
 * @param string $messagehtml html version of email (will send both html and text)
 * @param array  $customheaders email headers
 * @throws EmailException
 * @throws EmailDisabledException
 */
function email_user($userto, $userfrom, $subject, $messagetext, $messagehtml = '', $customheaders = null)
{
    global $IDPJUMPURL;
    static $mnetjumps = array();
    if (!get_config('sendemail')) {
        // You can entirely disable Mahara from sending any e-mail via the
        // 'sendemail' configuration variable
        return true;
    }
    if (empty($userto)) {
        throw new InvalidArgumentException("empty user given to email_user");
    }
    if (isset($userto->id) && empty($userto->ignoredisabled)) {
        $maildisabled = property_exists($userto, 'maildisabled') ? $userto->maildisabled : get_account_preference($userto->id, 'maildisabled') == 1;
        if ($maildisabled) {
            throw new EmailDisabledException("email for this user has been disabled");
        }
    }
    // If the user is a remote xmlrpc user, trawl through the email text for URLs
    // to our wwwroot and modify the url to direct the user's browser to login at
    // their home site before hitting the link on this site
    if (!empty($userto->mnethostwwwroot) && !empty($userto->mnethostapp)) {
        require_once get_config('docroot') . 'auth/xmlrpc/lib.php';
        // Form the request url to hit the idp's jump.php
        if (isset($mnetjumps[$userto->mnethostwwwroot])) {
            $IDPJUMPURL = $mnetjumps[$userto->mnethostwwwroot];
        } else {
            $mnetjumps[$userto->mnethostwwwroot] = $IDPJUMPURL = PluginAuthXmlrpc::get_jump_url_prefix($userto->mnethostwwwroot, $userto->mnethostapp);
        }
        $wwwroot = get_config('wwwroot');
        $messagetext = preg_replace_callback('%(' . $wwwroot . '([\\w_:\\?=#&@/;.~-]*))%', 'localurl_to_jumpurl', $messagetext);
        $messagehtml = preg_replace_callback('%href=["\'`](' . $wwwroot . '([\\w_:\\?=#&@/;.~-]*))["\'`]%', 'localurl_to_jumpurl', $messagehtml);
    }
    require_once 'phpmailer/PHPMailerAutoload.php';
    $mail = new PHPMailer(true);
    $mail->CharSet = 'UTF-8';
    $smtphosts = get_config('smtphosts');
    if ($smtphosts == 'qmail') {
        // use Qmail system
        $mail->IsQmail();
    } else {
        if (empty($smtphosts)) {
            // use PHP mail() = sendmail
            $mail->IsMail();
        } else {
            $mail->IsSMTP();
            // use SMTP directly
            $mail->Host = get_config('smtphosts');
            if (get_config('smtpuser')) {
                // Use SMTP authentication
                $mail->SMTPAuth = true;
                $mail->Username = get_config('smtpuser');
                $mail->Password = get_config('smtppass');
                $mail->SMTPSecure = get_config('smtpsecure');
                $mail->Port = get_config('smtpport');
                if (get_config('smtpsecure') && !get_config('smtpport')) {
                    // Encrypted connection with no port. Use default one.
                    if (get_config('smtpsecure') == 'ssl') {
                        $mail->Port = 465;
                    } elseif (get_config('smtpsecure') == 'tls') {
                        $mail->Port = 587;
                    }
                }
            }
        }
    }
    if (get_config('bounces_handle') && !empty($userto->id) && empty($maildisabled)) {
        $mail->Sender = generate_email_processing_address($userto->id, $userto);
    }
    if (empty($userfrom) || $userfrom->email == get_config('noreplyaddress')) {
        if (empty($mail->Sender)) {
            $mail->Sender = get_config('noreplyaddress');
        }
        $mail->From = get_config('noreplyaddress');
        $mail->FromName = isset($userfrom->id) ? display_name($userfrom, $userto) : get_config('sitename');
        $customheaders[] = 'Precedence: Bulk';
        // Try to avoid pesky out of office responses
        $messagetext .= "\n\n" . get_string('pleasedonotreplytothismessage') . "\n";
        if ($messagehtml) {
            $messagehtml .= "\n\n<p>" . get_string('pleasedonotreplytothismessage') . "</p>\n";
        }
    } else {
        if (empty($mail->Sender)) {
            $mail->Sender = $userfrom->email;
        }
        $mail->From = $userfrom->email;
        $mail->FromName = display_name($userfrom, $userto);
    }
//.........这里部分代码省略.........

/**
 * Send an email to a specified user
 *
 * @uses $CFG
 * @uses $FULLME
 * @uses SITEID
 * @param user $user  A {@link $USER} object
 * @param user $from A {@link $USER} object
 * @param string $subject plain text subject line of the email
 * @param string $messagetext plain text version of the message
 * @param string $messagehtml complete html version of the message (optional)
 * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
 * @param string $attachname the name of the file (extension indicates MIME)
 * @param bool $usetrueaddress determines whether $from email address should
 *          be sent out. Will be overruled by user profile setting for maildisplay
 * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
 *          was blocked by user and "false" if there was another sort of error.
 */
function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '', $attachment = '', $attachname = '', $usetrueaddress = true, $replyto = '', $replytoname = '')
{
    global $CFG, $FULLME;
    include_once $CFG->libdir . '/phpmailer/class.phpmailer.php';
    /// We are going to use textlib services here
    $textlib = textlib_get_instance();
    if (empty($user)) {
        return false;
    }
    // skip mail to suspended users
    if (isset($user->auth) && $user->auth == 'nologin') {
        return true;
    }
    if (!empty($user->emailstop)) {
        return 'emailstop';
    }
    if (over_bounce_threshold($user)) {
        error_log("User {$user->id} (" . fullname($user) . ") is over bounce threshold! Not sending.");
        return false;
    }
    $mail = new phpmailer();
    $mail->Version = 'Moodle ' . $CFG->version;
    // mailer version
    $mail->PluginDir = $CFG->libdir . '/phpmailer/';
    // plugin directory (eg smtp plugin)
    $mail->CharSet = 'UTF-8';
    if ($CFG->smtphosts == 'qmail') {
        $mail->IsQmail();
        // use Qmail system
    } else {
        if (empty($CFG->smtphosts)) {
            $mail->IsMail();
            // use PHP mail() = sendmail
        } else {
            $mail->IsSMTP();
            // use SMTP directly
            if (!empty($CFG->debugsmtp)) {
                echo '<pre>' . "\n";
                $mail->SMTPDebug = true;
            }
            $mail->Host = $CFG->smtphosts;
            // specify main and backup servers
            if ($CFG->smtpuser) {
                // Use SMTP authentication
                $mail->SMTPAuth = true;
                $mail->Username = $CFG->smtpuser;
                $mail->Password = $CFG->smtppass;
            }
        }
    }
    $supportuser = generate_email_supportuser();
    // make up an email address for handling bounces
    if (!empty($CFG->handlebounces)) {
        $modargs = 'B' . base64_encode(pack('V', $user->id)) . substr(md5($user->email), 0, 16);
        $mail->Sender = generate_email_processing_address(0, $modargs);
    } else {
        $mail->Sender = $supportuser->email;
    }
    if (is_string($from)) {
        // So we can pass whatever we want if there is need
        $mail->From = $CFG->noreplyaddress;
        $mail->FromName = $from;
    } else {
        if ($usetrueaddress and $from->maildisplay) {
            $mail->From = $from->email;
            $mail->FromName = fullname($from);
        } else {
            $mail->From = $CFG->noreplyaddress;
            $mail->FromName = fullname($from);
            if (empty($replyto)) {
                $mail->AddReplyTo($CFG->noreplyaddress, get_string('noreplyname'));
            }
        }
    }
    if (!empty($replyto)) {
        $mail->AddReplyTo($replyto, $replytoname);
    }
    $mail->Subject = substr(stripslashes($subject), 0, 900);
    $mail->AddAddress($user->email, fullname($user));
    $mail->WordWrap = 79;
    // set word wrap
    if (!empty($from->customheaders)) {
//.........这里部分代码省略.........