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Cybersecurity · head to head

Proofpoint vs Tenable Nessus

Proofpoint logo

Proofpoint

Cybersecurity

Email security and data protection suite from a private company owned by Thoma Bravo, licensed per user with modules sold separately.

From
$6/month
Rated
-
Full reviewWebsite
Tenable Nessus logo

Tenable Nessus

Cybersecurity

Network vulnerability scanner

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Tenable Nessus has a free tier, so it costs nothing to try first.
  • Each has a real cost: Proofpoint licensing is per user per year with each capability as a separate stock item, so the platform shown in a proof of concept is normally several products, and adding awareness training, data loss prevention or insider threat monitoring later is a fresh negotiation rather than enabling a feature.; Tenable Nessus nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • They diverge on capability: Proofpoint covers Inline secure email gateway, Tenable Nessus covers Network scanning.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Proofpoint and Tenable Nessus actually diverge.

Attributes where Proofpoint and Tenable Nessus differ
AttributeProofpointTenable Nessus
Starting price$6/monthFree
Free tierNoYes
PlatformsEmail, Cloud, WebWindows, Linux, Macos, Cloud

Identical on both: pricing model (subscription), user rating (Not yet rated), category (Cybersecurity), founded (2002).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Proofpoint

  • Inline secure email gateway
  • Attachment sandboxing
  • URL rewriting and click-time analysis
  • Threat Response Auto-Pull
  • Email Fraud Defense
  • Security awareness training
  • Insider Threat Management
  • Enterprise DLP

Only in Tenable Nessus

  • Network scanning
  • Vulnerability detection
  • Configuration assessment
  • Malware detection
  • Compliance checking
  • Cloud security assessment
  • Mobile scanning
  • API access

What people use each for

The jobs each tool is most often brought in to do.

Proofpoint

  • A regulated organisation that needs a filtering layer, DMARC enforcement and archiving with an auditable trail across all threenot Tenable Nessus
  • An organisation that suffered a business email compromise and must show its board a control that stops delivery rather than remediating afterwardsnot Tenable Nessus
  • Concentrating stronger controls and training on the specific individuals who actually receive targeted attacks rather than applying uniform policynot Tenable Nessus
  • Retracting a phishing message from thousands of mailboxes after the verdict changes, including copies that were forwarded internallynot Tenable Nessus

Tenable Nessus

  • Vulnerability scanning of servers, network devices and web applicationsnot Proofpoint
  • Configuration and compliance auditing against hardening benchmarksnot Proofpoint
  • Point in time assessments by consultants and penetration testersnot Proofpoint

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Proofpoint

  • Licensing is per user per year with each capability as a separate stock item, so the platform shown in a proof of concept is normally several products, and adding awareness training, data loss prevention or insider threat monitoring later is a fresh negotiation rather than enabling a feature.
  • It sits inline with MX records pointed at it, so any service degradation is a mail outage for the entire organisation, and both migrating on and migrating off are cutovers with queueing, rollback planning and a real risk of message loss.
  • Most customers on Microsoft 365 E5 or Google Workspace Enterprise are already paying for native filtering, so Proofpoint is a second licence layered over a capability the organisation owns, and that comparison is raised by finance at every single renewal.
  • The administration console carries a decade of acquisitions: the classic gateway policy routes and filters do not share a model with the newer module interfaces, rule evaluation is order-sensitive in ways that surprise untrained administrators, and mistakes there silently change what is delivered.
  • Quarantine management is a standing helpdesk workload because legitimate bulk mail, invoices and supplier notifications are held, and unless end-user digests are configured and users are taught to use them, the security team becomes the mail release desk.

Tenable Nessus

  • Nessus Professional is $4,790 for one year, sold as an annual licence rather than a per scan or usage based fee
  • Support beyond the base entitlement costs an extra $400 per year for Advanced Support with 24x365 phone and chat access
  • The on demand training course is a separate $275 purchase for a single person for one year
  • Multi year discounts require paying for two or three years up front

Pricing, plan by plan

Proofpoint

$6/month
  • Email Protection$6/month
    • Per user
    • Advanced threat detection
    • Data loss prevention
  • Compliance$8/month
    • All Email Protection
    • Archive & search
    • eDiscovery
  • Advanced Threat$10/month
    • All Compliance features
    • Targeted attack detection
    • Behavior analytics

Tenable Nessus

Free
  • Nessus EssentialsFree
    • Up to 16 ips
    • Network scanning
    • Vulnerability assessment
  • Nessus Professional$2600/year
    • Unlimited targets
    • Enterprise features
    • Advanced analytics
  • Nessus Expert$5200/year
    • All Professional features
    • Cloud integration
    • Advanced reporting

Which should you pick?

Choose Proofpoint if

  • You need inline secure email gateway.
  • You work on Email, Cloud, Web.
  • You also want attachment sandboxing.
Proofpoint review

Choose Tenable Nessus if

  • You need network scanning.
  • You want to start without paying.
  • You work on Windows, Linux, Macos, Cloud.
  • You also want vulnerability detection.
Tenable Nessus review

Questions people ask

Is Proofpoint or Tenable Nessus better?
Neither clearly leads. Proofpoint starts at $6/month and Tenable Nessus at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Proofpoint or Tenable Nessus?
Tenable Nessus has a free tier; the other does not. Paid plans start at $6/month for Proofpoint and Free for Tenable Nessus.
Does Proofpoint or Tenable Nessus run on more platforms?
Proofpoint runs on Email, Cloud, Web. Tenable Nessus runs on Windows, Linux, Macos, Cloud.
Can I use Tenable Nessus for free?
Yes. Tenable Nessus has a free tier, so you can try it without paying. Proofpoint starts at $6/month.
What is Proofpoint best used for?
Proofpoint is most often used for a regulated organisation that needs a filtering layer, dmarc enforcement and archiving with an auditable trail across all three, an organisation that suffered a business email compromise and must show its board a control that stops delivery rather than remediating afterwards, concentrating stronger controls and training on the specific individuals who actually receive targeted attacks rather than applying uniform policy, retracting a phishing message from thousands of mailboxes after the verdict changes, including copies that were forwarded internally. Of those, a regulated organisation that needs a filtering layer, dmarc enforcement and archiving with an auditable trail across all three and an organisation that suffered a business email compromise and must show its board a control that stops delivery rather than remediating afterwards are not what Tenable Nessus is typically brought in for.
What can Proofpoint do that Tenable Nessus cannot?
Proofpoint covers Inline secure email gateway, Attachment sandboxing, URL rewriting and click-time analysis, Threat Response Auto-Pull. Tenable Nessus covers Network scanning, Vulnerability detection, Configuration assessment, Malware detection.

Answered from the vendors’ own pages

Proofpoint: Does it replace Microsoft Defender for Office 365?

Functionally it overlaps heavily, and running both means paying twice for filtering. Most Proofpoint customers on Microsoft 365 keep Defender licensed because it is bundled in E5 and use Proofpoint as the inline gateway. Expect to justify that duplication annually.

Tenable Nessus: What are the three Nessus offerings?

Nessus Essentials is a free introductory offering for educators, students, and career starters, limited to 16 IPs for scanning. Nessus Professional is designed for consultants and SMBs, providing unlimited IT scans across any location. Nessus Expert is the premium offering extending Professional with web application scanning, infrastructure-as-code scanning, and external attack surface assessment up to 5 domains.

Source
Proofpoint: Who owns Proofpoint?

Thoma Bravo, a private equity firm, which took the company private in 2021. It has continued to acquire since, including Tessian, Normalyze and Hornetsecurity, which is why the portfolio spans so many adjacent categories.

Tenable Nessus: What OS platforms does Nessus support?

Nessus runs on Debian/Kali Linux, Fedora, FreeBSD, Mac OS X, Red Hat/CentOS, SUSE Linux, Ubuntu, and various Windows versions including Server 2008, 2012, and Windows 7-10.

Source
Proofpoint: Do I have to change my MX records?

For the gateway, yes. That is what makes it inline and able to block before delivery. Some newer capabilities integrate through the mailbox API instead, but the core protection model is MX-level.

Tenable Nessus: Can I use Nessus to scan third-party networks as a consultant?

Yes, Tenable permits you to use Nessus to scan third-party networks. Nessus Professional is ideal for consultants.

Source
Proofpoint: Is security awareness training included?

No, it is a separate subscription. It integrates well with the threat data, so training can target the users actually being attacked, but it is a distinct line item on the quote.

Tenable Nessus: Can Nessus perform PCI external scanning?

Yes, you can use Nessus Professional to perform external network scans as required by the PCI DSS 11.2.2 requirement.

Source
Proofpoint: What does Threat Response Auto-Pull actually do?

It removes messages from mailboxes after delivery when the verdict changes, including copies that users forwarded internally. It is the answer to the case where a link was clean at delivery and weaponised an hour later.

Tenable Nessus: What additional features does Nessus Expert provide?

Web application scanning, which is dynamic application security testing (DAST) providing comprehensive visibility and insight into web application security issues; scanning code repositories for vulnerabilities; and assessing external attack surface with subdomain discovery.

Source
Tenable Nessus: What support options exist for Nessus Professional?

Standard Support includes software upgrades, patches, plugin access, and 24x7 support via chat and community portal. Advanced Support adds 24x7 phone access and committed SLAs: P1 less than 2 hours, P2 less than 4 hours, P3 less than 12 hours, P4 less than 24 hours.

Source
Tenable Nessus: How frequently are Nessus plugins updated?

Nessus plugins are updated daily, based on when vendors and security research sites publish new vulnerabilities.

Source
Tenable Nessus: How does licensing work in virtual machine environments?

Whether you are using Nessus in a physical or a virtual environment, the IP addresses or hosts that you are scanning from must be licensed.

Source
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