MailShield (“the App”, “we”, “us”, “our”) is a Shopify app that helps merchants block fake, disposable, and mistyped email addresses at checkout and flag risky orders afterwards. This policy explains what data the App accesses, how it is used, and how it is protected.
1. Who we are
MailShield is operated by Stackedboost. For any privacy question or request, contact us at admin@stackedboost.com.
2. Data we access
When a merchant installs the App and authorizes it through Shopify, we access:
Store information — your shop domain and an offline access token, used to operate the App and call the Shopify Admin API on your behalf.
Customer email addresses:
At checkout: our Shopify checkout-validation Function checks the buyer’s email to block disposable, mistyped, invalid, or merchant-blocklisted addresses. The Function runs inside Shopify and sends nothing to our servers.
Checkout events (all plans): Shopify also sends us a checkouts/create webhook with the buyer’s email, so the dashboard can show which risky addresses were stopped. Only risky addresses are recorded. On the Free plan we keep a masked form (first letter and domain, for example j***@example.com), never the full address.
After an order is placed (all plans): Shopify sends us the order via the orders/create webhook. We count it toward the Free plan’s monthly allowance and score the email in memory. On the Free plan nothing about the customer is stored. On paid plans we store a risk log for the order (see section 4).
First-run order scan (all plans, once): when the app is first opened we read the store’s last 60 days of orders and check their email addresses in memory. We keep the counts and up to 50 findings (order ID, order number, email domain and problem type), not the email addresses.
Order metadata: order ID, name, and existing tags/notes, so we can add a risk tag and note (paid plans).
Merchant information: your custom blocked-domain list, alert email, and your store’s own contact email from Shopify, which we use to email you about the app.
We do not collect or store payment information, IP addresses, geolocation, postal addresses or phone numbers, even where Shopify includes them in the data it sends us.
3. How we use the data
Detect disposable/temporary email domains, common typos, invalid formats, and domains on the merchant’s blocklist.
Perform a DNS/MX lookup on the email domain (not the full address) to check deliverability (Advanced plan).
Tag flagged orders and add a risk note in the merchant’s Shopify admin.
Send the merchant an email alert for high-risk orders (if enabled).
We do not sell, rent, or share customer data, and we do not use it for advertising or any purpose beyond the risk scoring described here.
4. Data we store and retention
Store settings (blocklist, alert email, plan) — kept while the App is installed.
Risk logs (paid plans: order ID, email, email domain and risk score; Free plan: masked email, domain and risk score of risky checkouts only): retained for 90 days, then automatically deleted.
First-run scan results (counts and up to 50 findings, no email addresses): retained for 90 days, then automatically deleted.
We store the minimum necessary to provide the dashboard and logs.
5. Data deletion
When you uninstall the App, we delete your store’s data, including risk logs, scan results and settings, straight away, without waiting for Shopify’s shop/redact request.
We honor Shopify’s customers/data_request, customers/redact, and shop/redact requests.
6. Sub-processors
Railway: application hosting and PostgreSQL database, United States (us-west).
Resend: risk alert emails to the merchant on paid plans. These include the flagged email address.
Google (Gmail): our emails to the merchant’s own address about the app. No customer data.
Telegram: internal notifications to our team about installs and plan changes. Store name and counts only, no customer data.
Shopify: the commerce platform the App runs on.
All sub-processors are bound by their respective data-protection terms.
7. Security
All data is transmitted over TLS/HTTPS.
Data at rest is stored in a managed PostgreSQL database with access restricted to the App.
All webhook requests are verified using Shopify’s HMAC signatures.
8. Your rights
Depending on your jurisdiction (e.g. GDPR, CCPA), you may have the right to access, correct, or delete personal data. Contact admin@stackedboost.com to exercise these rights.
9. Changes to this policy
We may update this policy from time to time; the “Last updated” date above will reflect any change.