Cybersecurity giant Proofpoint has announced plans to acquire Hornetsecurity, a German company known for securing Microsoft 365 environments, in a deal reportedly worth around $1 billion. The acquisition marks a strategic move to strengthen Proofpoint’s position in cloud-based email and collaboration security—just as the company is rumored to be preparing for a second IPO.
Founded in 2007 and headquartered in Hanover, Hornetsecurity has long focused on protecting Microsoft 365 users from email-based threats, data loss, and compliance issues. Backed by TA Associates, PSG Equity, and Verdane, the company last raised a growth round in 2022. It now brings over $160 million in annual recurring revenue, with more than 20% year-over-year growth, making it one of Europe’s top-performing mid-size cybersecurity firms.
Proofpoint Doubles Down on Growth Ahead of Possible IPO
Proofpoint, currently owned by private equity giant Thoma Bravo, has acquired at least 25 companies to date—including venture-backed data security platform Normalyze last October. Thoma Bravo took Proofpoint private in 2021 through a $12.3 billion deal, and now speculation is swirling that Proofpoint could return to public markets soon. If true, the Hornetsecurity acquisition positions it well by boosting recurring revenue and expanding its European and Microsoft-focused customer base.
The deal follows a sharp uptick in cybersecurity funding and consolidation. VC-backed cyber startups raised $2.7 billion in Q1 2025, a 29% jump from the previous quarter. The sector’s momentum was further amplified by Alphabet’s $32 billion planned acquisition of Wiz in March—now considered the largest-ever venture-backed cybersecurity buyout.
Why Hornetsecurity Makes Strategic Sense
Hornetsecurity’s focus on Microsoft 365 aligns perfectly with Proofpoint’s strengths in threat intelligence and compliance. The acquisition enhances Proofpoint’s ability to secure business-critical collaboration tools, especially as enterprises continue to migrate to cloud-based systems.
By integrating Hornetsecurity’s cloud-native platform and expanding its European footprint, Proofpoint can deliver stronger protection across email, files, and user identities—all while appealing to enterprise IT teams looking for integrated solutions.
With recurring revenue locked in and a growing customer base, the deal is a win on multiple fronts: it offers Thoma Bravo a valuable asset for a potential IPO, strengthens Proofpoint’s product portfolio, and reflects broader investor appetite for cybersecurity growth stories in 2025.
