Post Back - Version 1.0.0.5 Post Back - (PB) Reply to craigslist.org classified posts without composing a new email message. PB allows you to browse posts and reply to them without using your email client or logging in to your web mail. Browse and respond all in the same interface. Now you can relax while checking the classifieds knowing that you don't have to minimize or maximize anything just to inquire about something that catches you eye. Best of all PB is 100% free of charge from patware.org!