Mimecast is a cloud-based email security provider. It began as an email management service for Microsoft's email products and now offers advanced email security against phishing and business email compromise, collaboration security, security awareness training and human risk management, email archiving, data protection and insider risk tools, DMARC Analyzer, and a managed service in which analysts review user-reported emails. It works with Microsoft Exchange, Microsoft 365, Google and on-premises email, and is delivered from the vendor's cloud.
Mimecast's global headquarters is in London, England. Since May 2022 it has been wholly owned by an affiliate of Permira, a British private equity firm, so it is not under EU ownership, and it is not open source. In 2018 Mimecast opened two replicated data centres in Frankfurt, part of a network that also included sites in the UK and the US, and a customer's region determines where its data is located. European organisations should confirm in the contract which region holds their data, and note that the UK is outside the EU.