- 1. Architectural commitment: Zero marketing trackers
- 2. Strictly necessary operational session storage
- 3. Client-side local storage & UI preferences
- 4. Self-hosted typography & asset isolation
- 5. Stripe checkout telemetry & fraud prevention
- 6. Browser controls & managing storage preferences
- 7. Frequently asked cookie questions
1. Architectural commitment: Zero marketing trackers
Most commercial websites embed dozens of invisible third-party tracking pixels (such as Google Analytics, Meta Pixel, LinkedIn Insight Tag, and marketing attribution beacons) that continuously transmit your browsing behavior to corporate data brokers. MailCheckup rejects this practice entirely.
Our website was designed under a strict Zero Tracking Protocol. We do not embed any third-party marketing trackers, retargeting scripts, or cross-site tracking beacons. We do not sell or monetize advertising real estate, and we do not participate in commercial data exchange pools.
2. Strictly necessary operational session storage
The marketing website (mailcheckup.net) is completely cookie-free. When you log into the customer portal (cp.mailcheckup.net), our servers set strictly necessary first-party HTTP cookies:
- Session Token (
mcu_session): A cryptographically signed token enabling your browser to maintain an authenticated workspace session. Protected byHttpOnly,Secure, andSameSite=Strictattributes. - Anti-CSRF Token (
mcu_csrf): A cryptographic nonce that protects against Cross-Site Request Forgery attacks when submitting verification jobs or updating API keys.
Under European Union ePrivacy Directive Article 5(3) and GDPR guidance, these cookies are classified as "strictly necessary" for service delivery and are legally exempt from consent banner requirements.
3. Client-side local storage & UI preferences
We use your browser's native localStorage API solely to store non-identifying client-side UI settings:
motion_reduce: Remembers whether you clicked "Pause motion" in our footer, respecting users with vestibular disorders.theme_mode: Remembers your interface display preference across page reloads.
Data stored in localStorage never leaves your device and is never transmitted to our backend servers.
4. Self-hosted typography & asset isolation
Many websites load web fonts from remote third-party CDNs (such as Google Fonts), causing the visitor's IP address and browser fingerprint to be logged by external entities. To preserve user privacy, MailCheckup self-hosts all WOFF2 typefaces (DM Sans and Space Grotesk) locally within our own /fonts/ directory.
Your web browser communicates exclusively with MailCheckup servers, preventing third-party font log tracking.
5. Stripe checkout telemetry & fraud prevention
When you purchase on-demand credit packs or configure a subscription, our payment modal interacts with Stripe Checkout (operated by Stripe, Inc.). Stripe sets fraud-prevention telemetry tokens (such as __stripe_mid) strictly during active checkout interactions to comply with mandatory PCI-DSS Level 1 security rules and prevent card-testing fraud.
Secuno LLC never receives or stores your credit card numbers or Stripe's fraud-detection tokens.
6. Browser controls & managing storage preferences
You can manage, inspect, or delete cookies at any time via your browser settings. You can also view our complete technical storage inventory below:
| Cookie / Key Name | Host Domain | Category | Lifespan | Purpose & Content |
|---|---|---|---|---|
| mcu_session | cp.mailcheckup.net | Strictly Necessary | 30 Days | Encrypted bearer token for authenticated customer workspace sessions. |
| mcu_csrf | cp.mailcheckup.net | Strictly Necessary | Session | Cryptographic anti-CSRF token protecting against cross-site request forgery. |
| theme_mode | mailcheckup.net (localStorage) | User Preference | Persistent | Stores light/dark UI display preference in browser memory. |
| motion_reduce | mailcheckup.net (localStorage) | User Preference | Persistent | Stores footer Pause motion toggle setting to assist vestibular comfort. |
| __stripe_mid | .stripe.com (Checkout only) | Fraud Prevention | 1 Year | Stripe merchant identifier used strictly for PCI fraud defense during checkout. |
7. Frequently asked cookie questions
Why doesn't MailCheckup display an annoying cookie consent banner?
Under the European Union ePrivacy Directive and GDPR Article 5(3), websites that use exclusively 'strictly necessary' cookies (such as authenticated user session tokens and CSRF protection) are exempt from cookie consent banner requirements. Because MailCheckup does not use non-essential advertising or analytics cookies, no banner is needed.
Does MailCheckup use Google Analytics, Meta Pixel, or LinkedIn Insight Tag?
No. MailCheckup does not use Google Analytics, Meta Pixel, LinkedIn Insight Tag, Hotjar, or any third-party behavioral profiling scripts on mailcheckup.net or cp.mailcheckup.net.
Are font requests tracked when I browse MailCheckup?
No. Unlike websites that link to external font servers (like Google Fonts or Adobe Fonts), MailCheckup self-hosts all WOFF2 font files directly on our own domain. Your IP address is never shared with external font providers.
What cookies are created when I log into the customer portal?
When you log into cp.mailcheckup.net, our system issues a cryptographically secure session token cookie (e.g. mcu_session) and an anti-CSRF token (mcu_csrf). Both cookies are first-party only, scoped to cp.mailcheckup.net, and protected by Secure and HttpOnly flags.
Does Stripe place cookies when I make a payment?
During payment checkout sessions, Stripe's embedded checkout iframe may set fraud-prevention telemetry tokens to comply with PCI-DSS Level 1 security and detect fraudulent card behavior. These tokens are used strictly for fraud prevention during active checkout.
How can I delete or block cookies in my browser?
You can inspect, clear, or block cookies at any time through your browser's privacy settings. Blocking all cookies may prevent you from logging into the authenticated customer portal (cp.mailcheckup.net), but will not affect reading public pages on mailcheckup.net.