Stop sending discount codes to fake emails.
Verify newsletter and discount signups for your webshop — catch typos and throwaway addresses at capture, and clean the list before every campaign.
The 10%-off signup is a magnet for fake addresses.
You run a webshop and offer a discount code for joining the newsletter. It works — the list grows. But some of those addresses were typed once to grab the code: typos that can never receive mail, throwaway inboxes that expire in an hour. The code goes out, the welcome email bounces, and every campaign after that is paying to mail addresses that don't exist.
Bounces aren't just waste — inbox providers watch your bounce rate, and a stale list drags real customers' emails toward spam. The fix has two halves: stop the junk at the door, and sweep the list before every big send.
Before a campaign: sweep the list
Export
Download your newsletter list from your shop or ESP as a CSV.
Upload
Drop it into ClearMX — the email column is detected automatically, duplicates and blank rows are skipped free.
Triage
Filter by verdict. Every flagged row shows the reason — no_mx, mailbox_not_found — so nothing is a mystery.
Export the safe rows
Download the deliverable-only CSV and load it back into your ESP before the send.
Product UI shown with sample data.
At capture: check before the code goes out
One POST from your signup handler, before you issue the discount. A dead address gets an inline "check your email" while the visitor is still on the page; a throwaway domain comes back risky, and your form decides — most shops allow the signup but skip the code.
One credit per call, from the same balance as the dashboard. Full request and response reference on the API page.
Every answer is explained — and nobody gets emailed.
Four honest outcomes
deliverable, risky, undeliverable — or an honest unknown when a mailbox can't be confirmed, instead of a confident guess.
A reason for every row
A 0–100 score plus a machine-readable reason (no_mx, mailbox_not_found, disposable_domain…) you can act on and show your team.
No email is ever sent
The mailbox probe talks to the receiving server but always stops before any message — the people on your list never see anything.
What a 25,000-subscriber list costs
One credit checks one address. Pay once — credits never expire, and there's no subscription required. The full rate schedule is on the pricing page.
Frequently asked questions
Yes — call the verification API from your signup form before you issue the discount code. One POST returns a verdict, a 0–100 score and the reason, so your form can reject a dead address while the customer is still on the page.
Disposable addresses come back as risky, not undeliverable — the mailbox may exist today and vanish tomorrow. You decide the policy: most shops skip the discount code for risky addresses but still allow the signup.
No. The mailbox check talks to the receiving server but always stops before any message is sent. Your subscribers never see anything.
Keep reading: Email List Cleaning: When and How to Do It · How to Reduce Your Email Bounce Rate