I change SignUp Status Mailer to be functional to write and send e-mail depening on language's user.
First, change database :
File : signup_status_mailer.install

function signup_status_mailer_schema() {
  return array(
    'signup_status_mailer_settings' => array(
      'description' => 'Stores signup status mailer e-mail text templates.',
      'fields' => array(
        'nid' => array(
          'type' => 'int',
          'unsigned' => TRUE,
          'not null' => TRUE,
          'description' => 'Foreign Key: the {node}.nid that a given message is associated with, or 0 for the site-wide default message templates.',
        ),
        'cid' => array(
          'type' => 'int',
          'unsigned' => TRUE,
          'not null' => TRUE,
          'description' => 'Foreign Key: the {signup_status_codes}.cid status code ID that a given message is for.',
        ),
             /* BEGIN ADD*/
           'lang' => array(
          'type' => 'varchar',
          'length' => '20',
          'not null' => TRUE,
          'description' => 'Foreign Key: {languages}.language language of mail  ',
        ),
             /* END ADD*/
        'action' => array(
          'type' => 'varchar',
          'length' => '255',
          'not null' => TRUE,
          'description' => "String that determines what status action the settings apply to, either 'add' when a status is first added to a signup, or 'update' when a status is modified.",
        ),
        'notification' => array(
          'type' => 'varchar',
          'length' => '255',
          'not null' => TRUE,
          'description' => "String that determines what kind of message notification to use for the given nid/cid pair. Can be 'none', 'default', or 'custom' for a per-node override.",
        ),
        'body' => array(
          'type' => 'text',
          'size' => 'big',
          'not null' => FALSE,
          'description' => 'The e-mail body template.',
        ),
        'subject' => array(
          'type' => 'varchar',
          'length' => '255',
          'not null' => FALSE,
          'description' => 'The e-mail subject template.',
        ),

      ),
        /* BEGIN CHANGE*/
      'primary key' => array('nid', 'cid','lang', 'action'),
        /* END CHANGE*/
    ),
  );
}

AND

function signup_status_mailer_update_6000() {
  $ret = array();

  $table = array(
    'description' => 'Stores signup status mailer e-mail text templates.',
    'fields' => array(
      'nid' => array(
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'description' => 'Foreign Key: the {node}.nid that a given message is associated with, or 0 for the site-wide default message templates.',
      ),
      'cid' => array(
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'description' => 'Foreign Key: the {signup_status_codes}.cid status code ID that a given message is for.',
      ),
              /* BEGIN ADD*/
           'lang' => array(
          'type' => 'varchar',
          'length' => '20',
          'not null' => TRUE,
          'description' => 'Foreign Key: {languages}.language language of mail  ',
        ),
             /* END ADD*/
      'action' => array(
        'type' => 'varchar',
        'length' => '255',
        'not null' => TRUE,
        'description' => "String that determines what status action the settings apply to, either 'add' when a status is first added to a signup, or 'update' when a status is modified.",
      ),
      'notification' => array(
        'type' => 'varchar',
        'length' => '255',
        'not null' => TRUE,
        'description' => "String that determines what kind of message notification to use for the given nid/cid pair. Can be 'none', 'default', or 'custom' for a per-node override.",
      ),
      'body' => array(
        'type' => 'text',
        'size' => 'big',
        'not null' => FALSE,
        'description' => 'The e-mail body template.',
      ),
      'subject' => array(
        'type' => 'varchar',
        'length' => '255',
        'not null' => FALSE,
        'description' => 'The e-mail subject template.',
      ),
    ),/*BEGIN CHANGE*/
      'primary key' => array('nid', 'cid','lang', 'action'),
/*END CHANGE */
  );

File : signup_status_mailer.module :


function signup_status_mailer_get_settings($node) {
     /* ADD */
global $user ;

  $nid = is_numeric($node) ? $node : $node->nid;
  static $settings = array();
  $get_defaults = empty($settings[0]);
  if (empty($settings[$nid])) {
    $settings[$nid] = array();
    if ($get_defaults && $nid != 0) {
         /* CHANGE*/
      $where = 'nid IN (0, %d) and lang=\'%s\'';
           /* END  CHANGE*/
      $settings[0] = array();
    }
    else {
         /* BEGIN CHANGE*/     
     $where = 'nid = %d and lang=\'%s\'';
      
    }
    $query = db_query("SELECT nid, cid, action, notification, body, subject FROM {signup_status_mailer_settings} WHERE $where", $nid,$user->language);
              /* END  CHANGE*/
    while ($data = db_fetch_array($query)) {
      $tmp_nid = $data['nid'];
      $cid = $data['cid'];
      $action = $data['action'];
      unset($data['nid'], $data['cid'], $data['action']);
      $settings[$tmp_nid][$cid][$action]= $data;
    }
  }
  return $settings[$nid];
}

File : signup_status_mailer.settings.inc :

function _signup_status_mailer_settings_form($status, $node, $site_setting = array(), $node_setting = array()) {

  $form = array(
    '#type' => 'fieldset',
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#attributes' => array('id' => 'status-settings-cid-' . $status['cid']),
  );
  if (empty($node)) {
    // Site-wide defaults.
    $form['#title'] = t("Default notification settings for status '@status'", array('@status' => $status['name']));

    // On the site-wide settings, the notification options are always the same.
    $notification_options = array(
      'none' => t('Disabled'),
      'default' => t('Enabled'),
    );
  }
  else {
    // Per-node settings.
    $form['#title'] = t("Notification settings for status '@status'", array('@status' => $status['name']));
  }

  // Save the status CID as a value in the form.
  $form['cid'] = array(
    '#type' => 'value',
    '#value' => $status['cid'],
  );
  /*BEGIN ADD*/
  // Save the status lang as a value in the form.
  $form['lang'] = array(
    '#type' => 'value',
    '#value' => $status['lang'],
  );
  /*END ADD*/
 foreach (array('add', 'update') as $action) {
    $form[$action] = array(
      '#prefix' => '<div class="signup-status-mailer-action">',
      '#suffix' => '</div>',
    );

AND

function signup_status_mailer_settings_submit($form, $form_state) {
//ADD
global $user;

  foreach ($form_state['values'] as $key => $status_values) {
    if (substr($key, 0, 21) == 'signup_status_mailer_') {
      foreach (array('add', 'update') as $action) {
        if (!empty($status_values[$action])) {
          $values = $status_values[$action];
          $values['action'] = $action;
                /*ADD*/
          $values['lang'] = $user->language;
                /*END ADD*/
          if (strpos($values['notification'], 'default-')) {
            $values['notification'] = 'default';
          }

AND

function _signup_status_mailer_save_settings($values, $include_text = TRUE) {
  $is_new = FALSE;
  if ($include_text) {
  /*CHANGE*/
    db_query("UPDATE {signup_status_mailer_settings} SET notification = '%s', body = '%s', subject = '%s' WHERE nid = %d AND cid = %d AND action = '%s' AND lang='%s'", $values['notification'], $values['email']['body'], $values['email']['subject'], $values['nid'], $values['cid'], $values['action'],$values['lang']);
    if (!db_affected_rows()) {
      db_query("INSERT INTO {signup_status_mailer_settings} (nid, cid, lang, action, notification, body, subject) VALUES (%d, %d, '%s', '%s', '%s', '%s', '%s')", $values['nid'], $values['cid'],$values['lang'], $values['action'], $values['notification'], $values['email']['body'], $values['email']['subject']);
      /*END CHANGE*/     
     $is_new = TRUE;
    }
  }
  else {
      /*BEGIN CHANGE*/
    db_query("UPDATE {signup_status_mailer_settings} SET notification = '%s' WHERE nid = %d AND cid = %d AND action = '%s' AND lang='%s'", $values['notification'], $values['nid'], $values['cid'], $values['action'],$values['lang']);
    if (!db_affected_rows()) {
      db_query("INSERT INTO {signup_status_mailer_settings} (nid, cid, lang, action, notification) VALUES (%d, %d, '%s', '%s', '%s')", $values['nid'], $values['cid'],$values['lang'], $values['action'], $values['notification']);
      /*END CHANGE*/  
  $is_new = TRUE;
    }
  }
  return $is_new;
}