Custom function for “Submit for Review” hook

You need Post Status Transitions actions

function notify_me_for_pending( $post ) {
  $user_info = get_userdata ($post->post_author);
  $strTo = array ('[email protected]');
  $strSubject="Fstoppers: " . $user_info->user_nicename . ' submitted a post';
  $strMessage=""" . $post->post_title . '" by ' . $user_info->user_nicename . ' was submitted a post for review at ' . wp_get_shortlink ($post->ID) . '&preview=true. Please proof.';
  wp_mail( $strTo, $strSubject, $strMessage );
}

add_action( 'draft_to_pending', 'notify_me_for_pending' );
add_action( 'auto-draft_to_pending', 'notify_me_for_pending' );