- Internal successor named to lead the company's next phase of execution and growth; Marc van Zadelhoff transitions to Board advisor
London – June 25, 2026 Mimecast, a leader in securing humans, data & AI, today announced that Ranjan Singh has been named Chief Executive Officer, effective immediately, to lead the company’s next phase of execution and platform-led growth. Singh succeeds Marc van Zadelhoff, who transformed Mimecast from a leader in email security into a unified human, data and AI risk platform during his time as CEO. Van Zadelhoff will continue to support the company as a Board advisor. Singh has also been appointed to the Mimecast Board of Directors.
“The convergence of human behavior, data, and AI has created a new risk surface that organizations weren’t built to handle in isolation,” said Ranjan Singh, Chief Executive Officer of Mimecast. “Securing and governing all three together is one of the most pressing challenges in cybersecurity today. Mimecast has spent years building toward this, and I’m deeply grateful to be trusted by the Board, our customers and colleagues to lead this next chapter.”
Singh joined Mimecast in 2025 as Chief Product & Technology Officer, where he further unified the product and engineering organizations, established a rigorous and innovative operating culture, and accelerated the development of the company’s AI-powered platform. During his tenure, Mimecast has delivered more than 100 net new products and enhancements over the past year. Singh also led the technical integration of Mimecast’s acquisitions in data security, compliance and collaboration into a unified platform for managing human and AI risk. Singh is also deeply engaged in Mimecast customer advisory boards and technical communities.
Prior to Mimecast, Singh spent more than three years as Chief Product Officer at Kaseya, where he held P&L responsibility across seven business units and a portfolio of more than 40 SaaS products, contributing to more than $1.5 billion in revenue. His leadership roles at Crestron Electronics and IPC Systems further cemented his reputation for delivering product excellence at scale.
“Marc led Mimecast through a significant strategic evolution, expanding the company well beyond email security into a platform built for the human and AI risk era. We are grateful for his contributions and the foundation he built and look forward to continuing to work with him in his board advisory capacity,” said Michail Zekkos, Mimecast Board Chair and Global Co-Head of Technology, Permira. “We're excited to have Ranjan step into the CEO role at a time when AI is opening unprecedented opportunities for mission-critical platforms that combine product innovation velocity with commercial scale. With deep product expertise, proven scale experience, and an understanding of Mimecast's culture, Ranjan is well-positioned to capture that opportunity and accelerate the platform into its next phase of growth.”
