Proofpoint Completes $1.8 Billion Acquisition of Hornetsecurity

Proofpoint has completed the acquisition of Germany-based Hornetsecurity, valuing the deal at $1.8 billion, according to SecurityWeek. Hornetsecurity, a Microsoft 365 security solutions provider, will operate as a dedicated business unit focused on MSPs, serving more than 12,000 MSPs and 125,000 customers. The acquisition adds nearly $200 million in annual recurring revenue to Proofpoint, which is experiencing a 20% year‑over‑year growth.

Hornetsecurity founder and CEO Daniel Hofmann will lead the new unit as Executive Vice President and General Manager. Sumit Dhawan, CEO of Proofpoint, said the combination complements Proofpoint’s enterprise‑grade solution and will enable protections for people, data, and AI agents across both enterprises and small businesses.

SecurityWeek notes that the deal, announced earlier as a reported $1 billion transaction, has culminated in a formal $1.8 billion value, with December 9, 2025 marking the publication date of the update.