The 11 cheapest cybersecurity

The cheapest provider in the Top 11 Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026 is Sublime Security, followed by Microsoft Defender for Office 365.

Why this answer

Sorted by published starting price, lowest first. We use each provider's lowest documented price band; where pricing is undisclosed, the entry falls to the bottom of the list.

Showing the top 11 of 11+ screened. Methodology at /methodology.

  1. #1Sublime Security(rank #11 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

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    Open detection-as-code with a real free tier.

    Full Sublime Security review · Compare: Sublime Security vs Microsoft Defender for Office 365 · Alternatives

  2. #2Microsoft Defender for Office 365(rank #4 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $2/mo+

    Native M365 protection, included in E5 at $0 extra.

    Full Microsoft Defender for Office 365 review · Alternatives

  3. #3Barracuda Email Protection(rank #5 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $3/mo+

    API inbox defense plus gateway at a mid-market price.

    Full Barracuda Email Protection review · Alternatives

  4. #4Trend Micro Email and Collaboration Security(rank #7 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $3/mo+

    API protection across email and collaboration apps.

    Full Trend Micro Email and Collaboration Security review · Alternatives

  5. #5Sophos Email(rank #9 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $3/mo+

    Email folded into the Sophos Central single console.

    Full Sophos Email review · Alternatives

  6. #6Mimecast(rank #3 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $4/mo+

    Security bundled with archiving and outage continuity.

    Full Mimecast review · Alternatives

  7. #7Check Point Harmony Email & Collaboration(rank #10 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

    $4/mo+

    Inline API that blocks threats before delivery.

    Full Check Point Harmony Email & Collaboration review · Alternatives

  8. #8Abnormal Security(rank #1 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

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    Behavioral AI that stops BEC gateways miss, API-deployed in under an hour.

    Full Abnormal Security review · Alternatives

  9. #9Proofpoint(rank #2 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

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    Full gateway plus DLP and encryption for regulated firms.

    Full Proofpoint review · Alternatives

  10. #10Cisco Secure Email Threat Defense(rank #6 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

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    Talos-backed detection wired into the Cisco stack.

    Full Cisco Secure Email Threat Defense review · Alternatives

  11. #11Fortinet FortiMail(rank #8 in Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026)

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    Flexible gateway wired into the Fortinet Security Fabric.

    Full Fortinet FortiMail review · Alternatives

Methodology: /methodology · No paid placement ever · Verified .