St. Louis-based Benchmark Email, which provides sales and marketing software, has expanded with the acquisition of another local firm. Benchmark Email on Tuesday said it acquired MarketVolt, an email marketing firm. Terms of the deal were not disclosed. “MarketVolt was founded and headquartered in St. Louis. We’re thrilled to join forces with Benchmark, a strong, industry-leading St. Louis company that is creating more tech jobs in our region and strengthening St. Louis’ position as an emerging technology hub,” former MarketVolt CEO Tom Ruwitch said.