Proofpoint vs Mimecast: which email security platform fits in 2026?

Both vendors now offer an API path that avoids MX changes. Mimecast launched Email Security, Cloud Integrated in 2022 and said it typically deploys in under five minutes; its product page says "connect via API in minutes". Proofpoint’s product page says "Deploy via API in 48 hours", a solution brief says 24 hours, and its buyer’s guide says minutes. The gateway modes of both take longer, because MX records, connectors and policies have to be migrated.

The practical difference is in what you deploy. If you want the gateway, both require an MX change and policy migration. If you want API-only, Mimecast Cloud Integrated is documented for Microsoft 365; check Google Workspace parity with each vendor for the mode you plan to use.

Neither Proofpoint nor Mimecast publishes current list prices. Older and third-party Proofpoint Essentials price sheets circulate online, but they are outdated or reseller figures and should not be used for budgeting. Expect per-user, quote-based pricing, with the final number driven by which add-ons you take: DMARC, archiving, DLP, awareness and account-takeover protection are all separate line items at one or both vendors.

• Ask both for a quote on the same scope: protection only, then protection plus the add-ons you really need.
• Ask whether archiving is priced per user or per storage, and what migration out of the archive costs.
• Ask for the API-only price separately from the gateway price.
• Ask about multi-year discounts and renewal caps in writing.

Proofpoint has been owned by Thoma Bravo since a ~$12.3B take-private completed on 31 August 2021. Since then it has acquired Tessian (cloud email security, 2023), Normalyze (data security, 2024), Nuclei (compliance archiving, 2025) and Hornetsecurity ($1.8B, completed 8 December 2025). Mimecast has been owned by funds advised by Permira since a ~$5.8B take-private in May 2022, and has since acquired Elevate Security and Code42 (2024).

Both are private-equity owned and both are building broad human-risk platforms around email. For EU buyers, the more relevant questions are contractual: which entity signs your DPA, where your mail is processed and stored, and which subprocessors are involved. Ask both vendors for their current subprocessor lists rather than relying on older data-centre announcements.

If you are fully on Microsoft 365 or Google Workspace and do not need a gateway, archive or continuity service, you are paying Proofpoint or Mimecast for a suite you will not use. Sentaro, which publishes this page, is our recommendation for that buyer.

• Fraud-first detection. Sentaro’s Message vector reads intent, sender identity, reply-chain context and suppliers that suddenly change banking details, and treats payload-free BEC as a core design target.
• One platform for mail and apps. The App vector inventories every app, AI tool and OAuth grant, with scope-level risk and one-click revocation.
• No migration project. Sentaro runs behind native filtering and behind an existing gateway, so you can trial it next to Proofpoint or Mimecast before deciding what to renew.
• A European vendor. Sentaro AB is based in Stockholm, and the service is hosted in Sweden on Microsoft Azure (see /en/legal/dpa).

Where Sentaro does not fit: it does not offer archiving, continuity, encryption or DLP, and it does not support on-premises Exchange. If those are requirements, Proofpoint or Mimecast remain the tools for that part of the job.