hook_menu_alter information
If all you are doing is adding to an existing menu, there is no need to use a menu alter. Instead stick with plain old hook_menu().

function ymlp_svm_mail_menu() {
  $items['admin/settings/ymlp-svm-mail/update'] = array(
    'title' =&gt; 'Update YMLP Accounts Manually',
    'page callback' =&gt; 'ymlp_update',
    'access callback' =&gt; TRUE,
    'type' =&gt; MENU_LOCAL_TASK,
  );
  return $items;
}


Don't forget to flush the menu cache after the module is installed