Restock Relay is a Shopify app for merchants who sell things that sell out. A shopper who finds a product unavailable can ask to be told when it returns. We email them once — when that exact variant is back — from the merchant’s own authenticated sending domain.
Are you a shopper who wants to stop receiving alerts? Here is how to unsubscribe.
Three steps. No mailing list is ever bought, rented, scraped or inferred: every address in Restock Relay was typed in by the person who owns it, on a merchant’s storefront, to request one specific alert.
A “Notify me” widget appears on the merchant’s product page when a variant is out of stock. The shopper enters their email address and submits it themselves. That submission is the opt-in, and it is scoped to that one product variant.
Shopify tells us when inventory changes. Before sending anything we re-check the live sellable quantity through Shopify’s API — we never send off the back of a webhook payload alone, and we wait out a short debounce so a stock correction does not become an email.
When the variant is genuinely available again, the shopper gets a single transactional alert for the product they asked about. It is not a newsletter, there is no follow-up sequence, and every message carries a working one-click unsubscribe.
Restock Relay only sends transactional restock alerts requested by the recipient. We do not send marketing campaigns, digests or promotions, and merchants cannot use Restock Relay to send them.
Every message includes RFC 8058 one-click unsubscribe
(List-Unsubscribe and List-Unsubscribe-Post) plus a
footer link that merchants cannot remove. One click, no login, no confirmation
step. The address is suppressed immediately.
Bounce and complaint notifications are processed automatically and the address is added to our suppression list, so it is not mailed again. Suppression is held at three levels: the app’s own list, the per-merchant sending tenant, and the account-wide suppression list.
Addresses are validated on the way in (syntax, MX record, disposable-domain blocklist). A merchant migrating a waitlist from another app may import a CSV — those addresses are re-validated, the first send is ramped in small batches, and it halts automatically if bounces exceed 5% of the first 100 results.
Billing is handled by Shopify. Paid plans include a 7-day free trial. You are never charged more than your plan price — there is no usage billing and no overage.
| Plan | Price | Emails / month | Includes |
|---|---|---|---|
| Free | $0 | 500 |
|
| Flat | $9 / month or $90 / year | Unlimited — full speed up to 25,000, rate-shaped above that |
|
| Pro | $19 / month or $190 / year | Unlimited — full speed up to 250,000, rate-shaped above that |
|
Above the full-speed threshold of your plan we slow delivery down and tell you — we never bill you extra and we never silently stop. On the Free plan, alerts beyond the 500-email allowance are queued rather than dropped: they are held for up to 72 hours, availability is re-checked immediately before sending, and anything still queued after that expires instead of arriving stale. The full terms are in the fair use policy.
On paid plans a setup wizard walks you through three DNS records so alerts leave from your domain, DKIM-signed with an aligned SPF and a custom MAIL FROM. We check the records for you and only switch over once DKIM verifies. Until then — and on the Free plan — alerts go from our shared authenticated domain with your store name in the From and your address in Reply-To. We never put your domain in the From line without verified DKIM.
$9 or $19 a month. A viral restock does not produce an invoice you did not agree to. If you outrun the full-speed threshold, we slow down and notify you — that is the whole mechanism.
Full subscriber CSV export on every plan, including Free, with addresses in the clear — not masked, not paywalled. If you leave, you take the list with you. Migrating in works too: import a CSV from your previous app.
From the shoppers themselves. Somebody typed their address into the “Notify me” form on a merchant’s out-of-stock product page and pressed submit. That is the only way an address enters Restock Relay through the widget. We never buy, rent or scrape addresses, and we do not read the merchant’s Shopify customer list — the app does not even request permission to.
Two read-only scopes: read_products and read_inventory.
That is enough to know a variant went from out of stock to in stock. No customer
data, no orders, no write access. If a shopper is logged into the store when they
subscribe, Shopify offers us their customer ID — we discard it and never store it.
One per request. Somebody who signs up for one variant gets one alert when that variant comes back. There is no drip sequence and no marketing.
One click, from any alert we send — the link is in the footer of every message, and mail clients that support RFC 8058 show their own unsubscribe button. Full instructions are on the unsubscribe help page.
No. Restock Relay does back-in-stock email alerts and nothing else.
Sending stops immediately: the store is deactivated, queued jobs are cancelled, and the store’s sending identity is torn down. Data erasure then follows Shopify’s data-deletion flow — see the privacy policy.