Sentaro is the best Mimecast alternative for EU teams on Microsoft 365 and Google Workspace: it connects over the Microsoft 365 and Google Workspace APIs in four minutes with no MX change and no agents; its BEC and vendor-fraud verdicts show their reasoning in the console, so you can audit them on your own mail; its App vector, live since Q3 2026, covers OAuth grants and AI tools in the same platform; its price, $6 per protected account per month with every feature included, is published (USD); and it is hosted in Sweden on Microsoft Azure, with subprocessors listed in the DPA. It runs alongside Defender or Google’s built-in filtering, so you can retire the gateway without giving up a first layer.
- Why Sentaro wins
- no gateway project: it connects over API next to Mimecast, so you can compare both on your own traffic before you move MX back to Microsoft or Google.
- Choose Sentaro if
- you are an EU team on Microsoft 365 or Google Workspace that wants BEC, QR-code and consent-phishing protection with a price you can see.
- Consider Mimecast, Proofpoint or Barracuda only if
- you need an MX gateway, on-premises or hybrid Exchange support, or archiving, DMARC and training from the same vendor.
What you are replacing: Mimecast at a glance
- Products
- Email Security Cloud Gateway (MX), Email Security Cloud Integrated (API), DMARC Analyzer, Email Archive, awareness training, Incydr (Code42), Aware
- Platforms
- Microsoft 365, Google Workspace, on-premises and hybrid Exchange
- Pricing
- Not publicly listed
- EU hosting
- Two Frankfurt data centres announced in 2018; current footprint not re-confirmed
- Ownership
- Private, owned by funds advised by Permira since May 2022
- Installed base
- 42,000+ organizations (vendor-stated)
Why teams look for a Mimecast alternative
The reasons below come from documented changes in the market, not from complaints. Each one is a reason to re-check fit at renewal, not proof that Mimecast is the wrong choice.
- The Microsoft baseline moved. Microsoft documents that Defender for Office 365 Plan 1 is included in Microsoft 365 Business Premium and is rolling out to Microsoft 365 E3 and Office 365 E3 from June 2026. Tenants that keep a gateway in front can end up paying for overlapping protection.
- Gateway versus API. A gateway sits in front of your MX record. API-based tools connect to the mailbox instead and also see internal mail. Mimecast sells both, so this can be a switch inside Mimecast.
- Pricing is quote-based. Mimecast does not publish list prices, which makes like-for-like budgeting harder at renewal.
- Ownership. Mimecast has been private, owned by funds advised by Permira, since May 2022. Some procurement teams re-run due diligence after a change of control.
- Data residency questions under NIS2 and DORA. Mimecast announced Frankfurt data centres in 2018; buyers often want the current hosting answer in writing.
Mimecast alternatives at a glance
Eleven options, including the ones we do not cover in detail below. Mimecast itself is in the detailed comparison table further down.
| Vendor | Type | Deploys via | Public price | Hosting | Best for |
|---|---|---|---|---|---|
| Sentaro (our pick) | API (ICES) | Microsoft 365 and Workspace APIs | $6 per account/month | Sweden (Microsoft Azure); see DPA | Our pick: EU teams on Microsoft 365 and Google Workspace |
| Defender for Office 365 | Native | Exchange Online mail flow | Plan 1 $2, Plan 2 $5 per user/month | EU Data Boundary | Microsoft 365 tenants already licensed |
| Proofpoint | Gateway and API | MX or Microsoft Graph | Quote | EU or US data centre (API product); some US processing | Enterprises wanting a full suite |
| Check Point Harmony Email | API (ICES), inline option | API, no MX change | Quote | Ireland region option | Inline-via-API and many SaaS apps |
| Barracuda | API (ICES) | API, no MX change | Quote | Gateway: Frankfurt, London; API modules: US | SMBs wanting backup and archive bundled |
| Abnormal AI | API (ICES) | API, no MX change | Quote | US or EU (Ireland), by subscription | Large enterprises |
| Hornetsecurity | Gateway, API or hybrid | MX, API or hybrid | Quote via partners | 12 regional data centres (vendor) | Microsoft 365 suites via MSPs |
| IRONSCALES | API (ICES) | API at mailbox level | Quote (tiers published) | AWS USA or Germany (subprocessor list) | SMBs and MSPs wanting simulation bundled |
| Libraesva | Gateway plus API | MX or API; cloud or on-prem | Quote | Local or chosen cloud | On-prem or private-cloud gateway in Europe |
| Cloudflare Email Security | Gateway, API or BCC | MX, API or journaling | Quote | Processing region selectable, incl. Germany | Cloudflare Zero Trust customers |
| Google Workspace built-in | Native | Gmail | Included in Workspace | Europe data region (edition-dependent) | Workspace tenants as a baseline |
The 7 Mimecast alternatives in detail
- 1
Sentaro
Our pickBest for: EU teams on Microsoft 365 and Google Workspace that want strong BEC and phishing protection without a gateway project.
Sentaro takes over detection from a Mimecast gateway from inside Microsoft 365 or Google Workspace: an API-based email and SaaS security platform, built in Stockholm and hosted in Sweden on Microsoft Azure, that runs alongside Defender or Google’s built-in filtering. Strengths: BEC, QR-code lures and OAuth consent phishing covered in one product; connects in four minutes with no MX change. $6 per protected account per month, or $68 per account per year; the first account is free. Prices in USD. What it does not replace: Mimecast’s archive, continuity, encryption, DMARC Analyzer and on-premises Exchange support.
Sentaro vs Mimecast Best for: Microsoft 365 tenants on Business Premium or E3 that want to cut a vendor.
Native filtering and threat protection inside Exchange Online. Strengths: nothing to route or connect; Plan 1 adds impersonation protection, Safe Links (Microsoft says this includes QR-code attacks) and Safe Attachments; Plan 2 adds Threat Explorer, automated investigation and attack simulation training. Limits, per Microsoft Learn as of 18 October 2026: Microsoft 365 only; archiving and OAuth app governance are separate Microsoft products.
Best for: Enterprises that want the closest like-for-like replacement, gateway included.
Email protection deployed via API or inline, with a large add-on portfolio. Strengths: both deployment modes; add-ons for DMARC (Email Fraud Defense), DLP, archiving, awareness training (ZenGuide) and account takeover; very large threat-intelligence base. Limits: pricing not published; its Core Email Protection API sheet says tenants are assigned to an EU or US data centre, with some processing and storage in the US; now also owns Hornetsecurity, so the two are no longer independent choices.
Best for: Teams that want API deployment but inline blocking, across many collaboration apps.
API-based protection (formerly Avanan) with an inline option. Strengths: Check Point says it inspects messages before they reach the inbox, configurable from monitor mode to inline prevention; covers Teams, Slack, OneDrive, SharePoint, Google Drive, Box and Dropbox; admin guide lists an Ireland data residency region. Limits, per checkpoint.com as of 18 October 2026: pricing not published; DMARC, archiving and training are add-ons.
Best for: SMBs and MSPs that want detection, backup, archiving and training on one contract.
An API-first bundle. Strengths: DMARC reporting, encryption and DLP in all plans; Microsoft 365 backup from Premium; archiving and training in Premium Plus; mature MSP program. Limits, per barracuda.com as of 21 October 2026: pricing not published; its trust center lists Frankfurt and London regions for Email Gateway Defense but only US regions for Impersonation Protection and Incident Response.
Best for: Large enterprises with a security team and budget for a behavioral platform.
Behavioral API email security, formerly Abnormal Security. Strengths: baselines per employee and vendor; states 60-second API deployment with no MX change; broad platform including account takeover, AI Phishing Coach and posture management. Limits, per abnormal.ai as of 21 October 2026: pricing not published; hosting on AWS in the US or the EU (Ireland), set by subscription (subprocessor list, July 2026); no archive or gateway mode.
Best for: Microsoft 365 customers buying through an MSP that want filtering, backup and archiving in one plan.
A tiered Microsoft 365 suite. Strengths: MX, API and hybrid modes; encryption from Plan 1, archiving from Plan 2, backup from Plan 3, DMARC management and training in Plan 4; vendor states 12 regional data centres. Limits, per hornetsecurity.com as of 18 October 2026: Google Workspace support not confirmed on vendor pages; pricing via partners only; now a Proofpoint company.
Mimecast and the alternatives side by side
| Capability | Sentaro | Mimecast | Defender for Office 365 | Proofpoint | Check Point Harmony Email | Barracuda | Abnormal AI |
|---|---|---|---|---|---|---|---|
| Deployment and platforms | |||||||
| Deployment | API, no MX change | Gateway (MX) or API | Native to Exchange Online | API or inline gateway | API with inline prevention | API-first, no MX change | API, no MX change |
| Microsoft 365 | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Google Workspace | Yes | Yes | No | Yes | Yes | Yes | Yes |
| On-premises Exchange | NoCloud mailboxes only | YesOn-premises and hybrid | PartialStandalone EOP | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented |
| Threat coverage | |||||||
| BEC and impersonation | YesMessage vector, live | Yes | YesImpersonation protection (Plan 1) | Yes | Yes | Yes | Yes |
| QR-code phishing | YesDecoded and destination analyzed | Yes | YesSafe Links (Plan 1) | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented | Yes |
| OAuth apps and shadow IT | YesApp vector, live | Not publicly documentedNot publicly documented | NoSeparate product: Defender for Cloud Apps | Not publicly documentedNot publicly documented | YesShadow IT detection | Not publicly documentedNot publicly documented | Not publicly documentedNot publicly documented |
| Suite extras | |||||||
| DMARC report management | NoReads DMARC posture as a signal only | Paid add-onDMARC Analyzer | NoEnforces DMARC; no report management | Paid add-onEmail Fraud Defense | Paid add-on | YesAll plans | Not publicly documentedNot publicly documented |
| Archiving | No | YesEmail Archive | NoSeparate product: Purview | Paid add-on | Paid add-on | YesPremium Plus | Not publicly documentedNot publicly documented |
| Awareness training | NoNot offered by design | Paid add-on | YesAttack simulation training (Plan 2) | Paid add-onZenGuide | Paid add-on | YesPremium Plus | YesAI Phishing Coach |
| Buying and data | |||||||
| Public pricing | Yes$6 per account/month | NoQuote-based | YesPlan 1 $2, Plan 2 $5 | NoQuote-based | NoQuote-based | NoQuote-based | NoQuote-based |
| EU hosting documented | YesHosted in Sweden on Microsoft Azure; see DPA | PartialFrankfurt data centres (2018) | YesEU Data Boundary | PartialEU or US data centre (API product); some US processing | YesIreland region option | PartialGateway: Frankfurt, London; API modules: US | PartialUS or EU (Ireland), by subscription |
“Not publicly documented” means we could not find it in the vendor’s public material on 18 October 2026, not that the capability is missing. Add-on means sold separately or in a higher tier.
- Yes
- Partial
- No
- On roadmap
- Paid add-on
- Not publicly documented
How to choose a Mimecast alternative
| Question | If yes | If no |
|---|---|---|
| Do you still need a gateway in front of MX (on-premises Exchange, journaling, outbound relay)? | Proofpoint, Hornetsecurity, Libraesva, or stay on Mimecast Cloud Gateway | API tools: Sentaro, Check Point, Abnormal, IRONSCALES, Barracuda |
| Do you use Mimecast Email Archive or continuity? | Plan the archive separately before you switch, or pick a suite vendor | You can compare detection tools on their own |
| Are you on Microsoft 365 Business Premium or E3? | You already have, or will have, Defender Plan 1. Buy a layer, not a replacement | Compare Defender Plan 1 at $2 per user/month against the alternatives |
| Do you run Google Workspace, or both platforms? | Exclude Microsoft-only options | Defender becomes the baseline to beat |
| Do you need EU hosting documented for NIS2, DORA or GDPR due diligence? | Ask each vendor for its DPA and subprocessor list before the trial | Weight detection and price higher |
Team size matters too. Lean IT teams of one to five people tend to need automatic remediation and few alerts. Larger security teams tend to want hunting, custom rules and SIEM integration.
Why Sentaro is our pick
Why Sentaro wins
- No gateway project: Sentaro connects over the Microsoft 365 and Google Workspace admin APIs in four minutes, with no agents and no MX change (your MX record stays where it is, which you can check in DNS), and shows historical mail within 15 minutes. It can run next to your current gateway before you move MX.
- Payload-free fraud, auditable: The Message vector, live since Q2 2026, scores intent, sender identity and relationship signals before interaction, including vendor-compromise and thread-hijack detection, and every verdict shows its reasoning in the console, so you can audit its BEC calls on your own mail.
- Apps in the same plan: The App vector, live since Q3 2026, inventories every app, AI tool and OAuth grant within 15 minutes of connecting, blocks consent phishing and revokes risky grants in one click.
- Price published: $6 per protected account per month, or $68 per year, every feature included, published on sentaro.com/en/pricing; the first account is free, so you can test it before talking to sales. Prices in USD.
- Hosting in writing: Hosted in Sweden on Microsoft Azure, with every subprocessor listed in the public DPA (sentaro.com/en/legal/dpa).
- You are moving off Mimecast Cloud Gateway and want to keep Defender or Google’s filtering as the first layer.
Consider another option only if
- You need an MX gateway, archiving, encryption, backup or DMARC report management. Sentaro does none of these.
- You run on-premises Exchange. Sentaro supports Microsoft 365 and Google Workspace only.
- You need account-takeover monitoring or a SOC 2 or ISO 27001 certificate today; see the roadmap and certification notes on this page.
How to switch from Mimecast without a gap in protection
A typical sequence for a Microsoft 365 tenant moving from Mimecast Cloud Gateway to native filtering plus an API layer.
- 01
List what Mimecast does for you today
Separate detection from everything else: archive, continuity, DMARC Analyzer, encryption, outbound rules, training. Each of those needs a new home or a decision to drop it.
- 02
Check the contract and the archive
Note the renewal and notice dates. Agree how archived mail will be exported or retained before the contract ends.
- 03
Connect the new layer in parallel
API tools need no MX change, so they can run next to Mimecast. Sentaro connects over API in four minutes and shows historical visibility within 15 minutes.
- 04
Compare on your own traffic
Run both for a few weeks. Review what each one flagged, missed and quarantined, especially BEC and supplier fraud.
- 05
Move MX back to Microsoft
Point MX to Exchange Online, update SPF, and remove inbound connectors and rules that only accept mail from Mimecast. Confirm Defender preset security policies are on.
- 06
Decommission and document
Turn off the gateway after the cut-over is stable. Record the change in your NIS2 or DORA ICT documentation and update your subprocessor register.
“We chose Sentaro because it gave us an extra layer of security without creating more work. It was quick to roll out and gave us the visibility we had been missing.”
From quarterly awareness training to zero clicks required.
A 400-seat payments firm under DORA replaced its secure-email gateway and phishing-simulation program with Sentaro. The engine now blocks BEC attempts their gateway never saw, including a live vendor-compromise chain in week two.
- 14
- BEC attempts blocked in the first month
- 4 min
- from contract to full deployment
- $0
- spent on phishing simulations since
Frequently asked questions
What is the best Mimecast alternative?
Sentaro. For EU teams on Microsoft 365 and Google Workspace, Sentaro is our pick as the best Mimecast alternative: it connects over API in four minutes with no MX change, catches BEC and vendor fraud before interaction, blocks OAuth consent phishing in the same platform and costs $6 per protected account per month (USD), hosted in Sweden on Microsoft Azure. If you need a gateway, archive or on-premises Exchange support, Proofpoint, Barracuda or Hornetsecurity are closer like-for-like options.
Is Mimecast better than Barracuda?
They solve slightly different problems. Mimecast offers both a gateway and an API product and supports on-premises Exchange. Barracuda describes an API-first product that bundles DMARC, encryption, DLP, backup, archiving and training in its plans. Neither publishes prices, so compare quotes for the same scope.
Which is better, Mimecast or Avanan?
Avanan is now Check Point Harmony Email & Collaboration. It is API-based with an inline option and covers many collaboration apps. Mimecast offers a gateway as well as an API product, plus an archive and on-premises Exchange support. Choose Check Point for API-first coverage, Mimecast if you need the gateway or archive.
Who is the parent company of Mimecast?
Mimecast is a private company owned by funds advised by Permira. The acquisition completed in May 2022 at about $5.8 billion, and Mimecast was delisted from Nasdaq.
Can I replace Mimecast with Microsoft Defender alone?
Some organizations do. Defender for Office 365 Plan 1 covers impersonation, Safe Links and Safe Attachments, and Plan 2 adds investigation and simulation training. It does not include archiving or Google Workspace. You can add an API-based layer on top for targeted BEC and payload-free fraud.
What happens to my Mimecast archive if I switch?
Archive migration is often the slowest part of a switch. Agree an export or retention plan with Mimecast before the contract ends, and decide where archived mail will live, for example Microsoft Purview or a dedicated archive. Detection tools like Sentaro do not archive mail.
Is there a Mimecast alternative hosted in the EU?
Yes. Microsoft 365 is an EU Data Boundary service for EU and EFTA tenants. Check Point documents an Ireland region. Hornetsecurity states 12 regional data centres. Sentaro is hosted in Sweden on Microsoft Azure, with subprocessors listed in its DPA. Ask every vendor for its subprocessor list.
Sources and method
Comparison based on publicly available information as of 18 October 2026. Product capabilities change; check each vendor’s current documentation. Trademarks belong to their owners. Corrections: contact Sentaro.
- Mimecast: Email Security (accessed 2026-10-18)
- Permira: Completes acquisition of Mimecast (2022)
- Datacentre News: Mimecast opens two Frankfurt data centres (2018)
- Microsoft Learn: Why do I need Microsoft Defender for Office 365? (accessed 2026-10-18)
- Microsoft: Defender for Office 365 pricing (accessed 2026-10-18)
- Microsoft Tech Community: Defender for Office 365 Plan 1 rolling out to Microsoft 365 E3 (2026-06-17)
- Microsoft Learn: EU Data Boundary (accessed 2026-10-18)
- Proofpoint: Core Email Protection (accessed 2026-10-18)
- Proofpoint: Proofpoint completes acquisition of Hornetsecurity (December 2025)
- Check Point: Harmony Email & Collaboration (accessed 2026-10-18)
- Check Point: Harmony Email & Collaboration admin guide, data residency
- Check Point: Acquires Avanan (2021)
- Barracuda: Email Protection (accessed 2026-10-18)
- Barracuda: Email Protection plans (accessed 2026-10-18)
- Abnormal AI: Inbound Email Security (accessed 2026-10-18)
- Hornetsecurity: 365 Total Protection (accessed 2026-10-18)
- IRONSCALES: Home page (accessed 2026-10-18)
- Libraesva: Home page (accessed 2026-10-18)
- Cloudflare docs: Email Security setup and deployment modes
- Google Workspace Admin Help: Data regions (accessed 2026-10-18)
- Google Workspace pricing (accessed 2026-10-18)
- Sentaro Data Processing Agreement and subprocessor list
- Abnormal AI: Subprocessors (updated 31 July 2026; accessed 2026-10-21)
- IRONSCALES: List of current sub-processors (PDF, December 2024; accessed 2026-10-21)
- Proofpoint: Data privacy information sheet, Core Email Protection API (updated 24 July 2026; accessed 2026-10-21)
- Barracuda Trust Center: Data center locations (accessed 2026-10-21)
- Cloudflare docs: Email Security regional processing (accessed 2026-10-21)