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Developer Tools · head to head

Atlantis vs Proofpoint

Atlantis logo

Atlantis

Developer Tools

Runs Terraform plan and apply from pull request comments, self-hosted and free

From
Free
Free plan
Yes
Full reviewWebsite
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
Free plan
No
Full reviewWebsite

The short version

  • Only Atlantis has a free tier, so it costs nothing to try first.
  • Each has a real cost: Atlantis there is no company, no service level agreement and no paid support at any price, and the six maintainers are volunteers with day jobs, which some risk committees will not accept for a component holding production cloud credentials.; 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.
  • They diverge on capability: Atlantis covers Pull request plans, Proofpoint covers Inline secure email gateway.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Atlantis and Proofpoint actually diverge.

Attributes where Atlantis and Proofpoint differ
AttributeAtlantisProofpoint
Starting priceFree$6/month
Pricing modelOpen source, no licence feesubscription
Free tierYesNo
PlatformsLinux, Docker, Kubernetes, Self-hostedEmail, Cloud, Web
CategoryDeveloper ToolsCybersecurity
FoundedUnknown2002

Identical on both: user rating (Not yet rated).

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 Atlantis

  • Pull request plans
  • Comment driven apply
  • Workspace locking
  • Policy checking
  • Multi-platform webhooks
  • Custom workflows

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

What people use each for

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

Atlantis

  • Making Terraform review meaningful by putting the actual plan output in front of the approvernot Proofpoint
  • Removing local applies and the credential sprawl that comes with every engineer holding production keysnot Proofpoint
  • Getting pull request driven infrastructure without paying a per-user subscription for a hosted platformnot Proofpoint
  • Enforcing Conftest policies as a blocking check before an apply can runnot Proofpoint

Proofpoint

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

Where each one falls short

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

Atlantis

  • There is no company, no service level agreement and no paid support at any price, and the six maintainers are volunteers with day jobs, which some risk committees will not accept for a component holding production cloud credentials.
  • The security surface is inherently sharp, because it is an internet-reachable webhook endpoint that executes applies with privileged credentials, gated by pull request comment authorisation that is coarse next to a real policy engine.
  • It is stateful, holding a working directory and lock database on local disk, so high availability and horizontal scaling are awkward and you own upgrades, webhook plumbing, secret rotation and the host itself.
  • It lacks the features that distinguish the commercial alternatives, with no native drift detection, no cost estimation, no managed state interface and no policy engine beyond the Conftest integration.
  • Terragrunt and monorepo layouts are not first-class, requiring hand-written custom workflows and repository configuration that becomes a growing maintenance burden as the number of repositories increases.

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.

Pricing, plan by plan

Atlantis

Free
  • AtlantisFree
    • Apache-2.0, no usage limits and no seat count
    • No commercial edition and no paid support tier
    • Community support through GitHub and the CNCF Slack channel

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

Which should you pick?

Choose Atlantis if

  • You need pull request plans.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want comment driven apply.
Atlantis review

Choose Proofpoint if

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

Questions people ask

Is Atlantis or Proofpoint better?
Neither clearly leads. Atlantis starts at Free and Proofpoint at $6/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Atlantis or Proofpoint?
Atlantis has a free tier; the other does not. Paid plans start at Free for Atlantis and $6/month for Proofpoint.
Does Atlantis or Proofpoint run on more platforms?
Atlantis runs on Linux, Docker, Kubernetes, Self-hosted. Proofpoint runs on Email, Cloud, Web.
Can I use Atlantis for free?
Yes. Atlantis has a free tier, so you can try it without paying. Proofpoint starts at $6/month.
What is Atlantis best used for?
Atlantis is most often used for making terraform review meaningful by putting the actual plan output in front of the approver, removing local applies and the credential sprawl that comes with every engineer holding production keys, getting pull request driven infrastructure without paying a per-user subscription for a hosted platform, enforcing conftest policies as a blocking check before an apply can run. Of those, making terraform review meaningful by putting the actual plan output in front of the approver and removing local applies and the credential sprawl that comes with every engineer holding production keys are not what Proofpoint is typically brought in for.
What can Atlantis do that Proofpoint cannot?
Atlantis covers Pull request plans, Comment driven apply, Workspace locking, Policy checking. Proofpoint covers Inline secure email gateway, Attachment sandboxing, URL rewriting and click-time analysis, Threat Response Auto-Pull.

Answered from the vendors’ own pages

Atlantis: Is there a company behind Atlantis?

No. It runs as a series of LF Projects under the Linux Foundation and is maintained by volunteers. There is no vendor to buy support from and no service level agreement.

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.

Atlantis: Is it a CNCF project?

No. It uses a channel in the CNCF Slack, which is often misread as membership, but the project sits under LF Projects rather than the CNCF.

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.

Atlantis: Does it work with OpenTofu?

Yes, there is a dedicated integration guide alongside Terraform, and it also has configuration for working with hosted Terraform backends.

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.

Atlantis: What does it not do that a paid platform does?

Drift detection, cost estimation, a managed state and run interface, and a real policy engine. Atlantis does pull request plan and apply well and stops there.

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.

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.

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