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Google Blocking App Access

How to resolve the "Error 400: Admin Policy Enforced", "This app is blocked", or “Google hasn’t verified this app” message when connecting Google Workspace accounts.

Updated over 2 months ago

The Potential Issue

When trying to connect a Google Workspace email to SendScale via OAuth, you may encounter an error screen from Google stating:

  • "Error 400: admin_policy_enforced"

  • "Access Blocked: SendScale has not completed the Google verification process"

The Cause

This is not a SendScale bug. This is a security setting within your organization's Google Workspace. Your IT Admin has set the "Third-Party App Access" policy to Restricted, meaning no apps can connect unless explicitly whitelisted.

The Solution (Admin Access Required)

You (or your IT Admin) must whitelist the SendScale App ID in the Google Admin Console.

Step 1: Open Google Admin

Log in to admin.google.com using a Super Admin account.

Step 2: Navigate to API Controls

Go to Security > Access and Data Control > API Controls.

Step 3: Manage Third-Party App Access

  1. Click "Manage Third-Party App Access".

  2. Click "Add App" > "OAuth App Name or Client ID".

  3. Search: Type "SendScale" in the search bar.

  4. Select: Hover over the SendScale app icon and click "Select."

Step 4: Grant Trusted Access

  1. Check the box for the OAuth Client ID.

  2. Select "Trusted" (This is the critical step).

  3. Click "Configure" or "Save".

Result: Wait 5-10 minutes for Google to propagate the change. Return to SendScale and retry the "Connect with Google" button. The error should be gone.

Additional Potential Issues

When connecting your Google account to SendScale, you may see a "Google hasn't verified this app" warning screen. This often includes a message stating that the app is unverified or that you should only continue if you know the developer.

The Cause

This is a standard security screen triggered by Google when an application requests access to sensitive data (like sending emails) before it has completed a specific stage of Google's manual OAuth review. Because SendScale requires high-level "Send" permissions to function, Google displays this warning as a precaution to ensure the user is aware of the access being granted.

The Solution (Bypass Warning)

You do not need to wait for a "verification" update to proceed. You can bypass this screen immediately to finish your setup.

Step 1: Click "Advanced"

On the "Google hasn't verified this app" screen, look for the Advanced link in the bottom-left corner of the white warning box.

Step 2: Proceed to SendScale

After clicking Advanced, a small sub-menu will appear. Click the link at the bottom that says: "Go to SendScale (unsafe)" (Note: Google labels all unverified third-party apps as "unsafe" by default; this is a standard procedural label.)

Step 3: Grant Permissions

You will be taken to the final permission screen. Review the access requirements and click Allow.

Step 4: Finalize Connection

You will be redirected back to SendScale. Your account is now connected via OAuth and ready for the warmup or sending phase.

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