Keller Postman LLC | 5,275 followers on LinkedIn. Power on Your Side: $3 Billion Secured for Clients | Keller Postman LLC is a national law firm that represents a broad array of clients as plaintiffs in complex litigation at the trial and appellate levels. We act for plaintiffs in federal and state court across a variety of claims and practice areas. We take on complicated cases—frequently class and mass actions, arbitrations or matters in multiple jurisdictions—where our legal and strategic counsel can add significant value.