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Email Unsubscriber is now CASA Tier 2 validated

Email Unsubscriber cleared ADA's CASA Tier 2. The validation unlocks Gmail support and confirms what we built behind the scenes.

Email Unsubscriber Team 2 min read
CASA Tier 2 validation badge

Google received the Letter of Validation confirming that Email Unsubscriber passed App Defense Alliance’s CASA Tier 2. CASA Tier 2 is the independent verification Google requires of every app that reads users’ emails in Gmail.

Email Unsubscriber passed CASA Tier 2, the independent security assessment Google requires of any app that reads Gmail. TAC Security, an ADA-authorized lab, ran 100+ automated checks plus a review of 20+ security aspects covering data handling, credentials, and access. The validation unlocked Gmail support and confirms our servers never touch your email.

TAC Security, Google’s authorized assessment lab, ran the assessment. The audit covered 100+ automated security checks against the Cloud Application Security Assessment (CASA) framework, plus a thorough review of 20+ security aspects covering data handling, credentials, access, and incidents.

Why it matters

  • Independent proof of our security claims. A third-party lab, authorized by ADA, reviewed our code and our operating practices. Outside validation now backs the word “secure” on our site.
  • Validation of “No access to email data.” A recurring theme in the review: “Where does user data live and how do you protect it?” Our answer is short. We don’t store users’ email data because we never access it. The scanner runs in the user’s browser. Our servers see nothing.
  • Formal sign-off on what we built. The assessment validates the architecture we picked from day one: read-only OAuth scopes, AES-256 encryption at rest, browser-side scanning, and one-off payments that remove the incentive to hoard data for retention metrics.

What this unlocks

We support Gmail now. Until today, Microsoft/Outlook was the only provider we supported. Gmail sat behind a “Coming soon” label pointing to our security page. With CASA validation in hand, Google finalized our verification, and Gmail accounts work today.

What’s next

We want Email Unsubscriber to reach more users. The roadmap covers more email providers, with custom integrations as a longer-term goal.

The validation took a few weeks of infrastructure improvements, paperwork, and back-and-forth with Google and the assessor. Outside validation backs a privacy claim better than self-reporting can, and that’s why we did it.

For anyone weighing an inbox tool, that same standard applies: independent proof beats a privacy promise. Are email unsubscribe apps safe? walks through the OAuth scopes and processing questions worth asking before you connect one.

Frequently asked questions

What is CASA Tier 2 validation?

CASA Tier 2 is the independent security verification Google requires of every app that reads users' emails in Gmail. It checks an app's code and operating practices against the App Defense Alliance's Cloud Application Security Assessment framework. Passing it means an authorized lab, not the app maker, confirmed the security claims.

Who ran Email Unsubscriber's CASA assessment?

TAC Security, one of Google's authorized assessment labs, ran the assessment. The audit covered more than 100 automated security checks against the CASA framework, plus a review of over 20 security aspects spanning data handling, credentials, access, and incidents. Google issued the Letter of Validation once the lab signed off.

Why does Google require CASA for Gmail apps?

Google requires CASA Tier 2 of any app that requests access to read Gmail messages. The assessment gives users independent proof that the app handles email data safely, rather than relying on the developer's own word. Until Email Unsubscriber cleared it, Gmail sat behind a Coming soon label.

Does Email Unsubscriber store my email data?

No. Email Unsubscriber never accesses your email data, so there is nothing to store. The scanner runs inside your browser, and the servers see none of your message content. The CASA review confirmed this architecture: read-only OAuth scopes, AES-256 encryption at rest, and browser-side scanning.

What did the CASA Tier 2 audit check?

The audit ran more than 100 automated security checks against the Cloud Application Security Assessment framework, plus a review of over 20 security aspects covering data handling, credentials, access, and incidents. It examined both the code and the operating practices behind Email Unsubscriber, not just a questionnaire.

Does Email Unsubscriber support Gmail now?

Yes. With CASA validation confirmed, Google finalized the verification and Gmail accounts work today. Before this, Microsoft and Outlook were the only supported providers, and Gmail sat behind a Coming soon label. The roadmap covers more email providers next.