Okay TorPM is site that seems to be down. It was at: http://4eiruntyxxbgfv7o.onion/pm/inbox.php? But even the root domain is down. And no, you do not need to use TorPM to contact vendors, simply use the pm system of the main SilkRoad site, encrypt your message to them using there public key (in GPA's clipboard) and send. Peace, DigitalAlch