Email Verifier
Automatically checks the authenticity of every new customer's email and tags them accordingly.
The app is currently active. Every new customer's email is
classified into one of three tiers: email_safe (SMTP confirmed),
email_risky (passes all checks but SMTP inconclusive), or
email_unsafe (failed).
Batch Verify Existing Customers
Select a customer segment to run all existing emails through the verification engine.
Each email is classified as safe, risky, or unsafe.
Unsafe emails tagged email_unsafe.
Note: SMTP confirmation is skipped in batch mode — emails that pass all other checks are tagged email_risky rather than email_safe.
How It Works
- A new customer is created on your Shopify store.
- Our server receives a customers/create webhook and runs the email through 7 layers including a live SMTP mailbox probe.
-
Safe — SMTP confirmed the mailbox exists. Tagged
email_safe. -
Risky — Passes all checks but SMTP was inconclusive (catch-all server, timeout, etc.). Tagged
email_risky. Not unsubscribed. -
Unsafe — Failed one or more checks or SMTP rejected the mailbox. Tagged
email_unsafe.
Automatic Webhook Management
The customers/create webhook is registered and managed automatically. It activates when you turn the app on and is removed when you turn it off — no manual setup required.
7-Layer Validation Engine
Every email passes through seven checks in sequence and is classified as Safe, Risky, or Unsafe. Only Unsafe emails trigger automatic unsubscription.
Syntax & Format +20 pts
Validates RFC 5321/5322 rules — correct structure, valid characters, proper domain format. Catches typos like user@ or user@domain.
DNS & MX Records +20 pts
Looks up the domain's mail exchange (MX) records. If the domain has no mail servers configured, no email can ever be delivered there.
Disposable Domain Detection +20 pts
Checks against a list of 4,000+ known throwaway providers (Mailinator, Guerrilla Mail, TempMail, etc.). These addresses are created to bypass sign-up gates and are discarded immediately after use.
Role-Based Address Detection +20 pts
Rejects generic shared inboxes — admin@, info@, noreply@, support@, etc. These belong to teams, not individual customers, so they're unsuitable for marketing.
Alias Normalisation informational
Detects when an address is an alias of another inbox. Gmail strips dots and plus-tags (f.i.r.s.t+tag@gmail.com → first@gmail.com). Yahoo strips hyphen-suffixes. The canonical address is stored so duplicate customers can be identified.
Typo Suggestion −10 pts if triggered
Compares the domain against common providers using Levenshtein distance. If gnail.com or yahooo.com is detected, a correction is suggested. The email is not blocked but its score is reduced to flag it for review.
SMTP Mailbox Probe tier deciding
Connects to the mail server over port 25 and sends a RCPT TO command without delivering any email. A 250 OK response confirms the mailbox exists → Safe. A 550 5.1.x definitive rejection → Unsafe. Timeouts, catch-all servers, or port blocks → Risky (inconclusive). This layer is skipped in batch mode.
Tier classification
Using Tags for Analysis & Segments
The app writes one of three tags to each customer profile. Use these in Shopify's customer segments to target or exclude audiences precisely.
email_safe
SMTP confirmed the mailbox exists and all validation layers passed. Highest confidence — use for campaigns, loyalty offers, and flows where deliverability is critical.
email_risky
Passed all validation checks but the SMTP result was inconclusive (catch-all server, timeout, or probe blocked). The address is likely real but not confirmed. Not unsubscribed from marketing — treat as a softer signal.
email_unsafe
Failed one or more checks (bad syntax, no MX records, disposable domain, role address) or SMTP definitively rejected the mailbox. Automatically unsubscribed from marketing. Route into a re-capture flow to collect a corrected address.
Segment Examples
Highest-confidence audience (Safe only)
customer_tags CONTAINS 'email_safe'
Use for newsletters, product launches, or any campaign where inbox placement is critical. SMTP-confirmed mailboxes only.
Broad deliverable audience (Safe + Risky)
customer_tags CONTAINS 'email_safe' OR customer_tags CONTAINS 'email_risky'
Includes confirmed and likely-real addresses. Good for general sends where you accept some bounce risk.
Exclude unsafe emails from campaigns
customer_tags NOT CONTAINS 'email_unsafe'
Add to any segment to filter out definitively bad addresses and protect your sender reputation.
Re-capture campaign (Unsafe)
customer_tags CONTAINS 'email_unsafe'
Target via SMS or on-site pop-up to collect a corrected email address.
Unclassified / pending customers
customer_tags NOT CONTAINS 'email_safe' AND customer_tags NOT CONTAINS 'email_risky' AND customer_tags NOT CONTAINS 'email_unsafe'
Customers who signed up before the app was installed. Run a batch job to classify them.
How to create a segment in Shopify
Go to Customers → Segments → Create segment in your Shopify Admin. Type one of the queries above into the segment builder and save. The segment updates automatically as new customers are verified.
Current plan:
Legacy plan — usage tracking is not available. Upgrade or downgrade at any time; the change takes effect after you approve the new charge in Shopify.
Auto-unsubscribe unsafe emails
When enabled, customers classified as email_unsafe are automatically
unsubscribed from Shopify marketing at the same time the tag is applied.
Risky emails are never auto-unsubscribed regardless of this setting.
Disable this if you manage marketing consent separately or want to
handle unsubscribes yourself.
App Status
Deactivating the app stops all new email verification and removes the customers/create webhook from Shopify. Existing tags are not removed. You can reactivate the app at any time from the Dashboard.