roundcubemail/program/lib/Roundcube/rcube_message.php
public function set_safe($safe = true)
    {
        $_SESSION['safe_messages'][$this->folder.':'.$this->uid] = $this->is_safe = $safe;
    }
public function set_safe($safe = true)
    {
        $_SESSION['safe_messages'][$this->folder.':'.$this->uid] = $this->is_safe = $safe;
    }
public function set_safe ( $ safe = true ) { $ _SESSION [ 'safe_messages' ] [ $ this -> folder . ':' . $ this -> uid ] = $ this -> is_safe = $ safe ; }
Set is_safe var and session data

@param bool $safe enable/disable
Set is_safe var and session data