Representatives from Material, Mimecast and Proofpoint did not immediately respond to requests for comment.
The challenge facing incumbents such as Mimecast and Proofpoint is less about losing customers and more about missing out on new business from young companies that go with a next-generation tool such as Abnormal, according to Mark Alley, an email security consultant in Alabama. But some companies have switched to Sublime from Mimecast and from Proofpoint, Kamdjou said.
Proofpoint appears to be aware of the challenge, having acquired AI startup Tessian last year. Sumit Dhawan, CEO of Proofpoint, said in October that the company was 12 to 18 months away from going public again. He said he saw interesting potential acquisition targets but that prices remained high.