Our guarantee: 99%+ accuracy, automatic Unknown refunds, and how your data is handled

You are trusting us with your email list, your contacts, your sender reputation, and your marketing budget. That is not something we take lightly. This page lays out exactly what we commit to — in plain English, with the actual code behind each commitment so you can verify they are real and not marketing language with no teeth.

99%+ verification accuracy

Our verification engine delivers 99%+ accuracy on every list it runs. That is the headline number, but the more useful framing is what it means for the statuses you see in your results.

When the engine returns safe, you can trust the mailbox is real and accepting mail at the moment of verification. When it returns invalid, the mailbox does not exist. When it returns disposable or spamtrap or role_account, there is a concrete, verifiable reason behind that flag. We are deliberately conservative — when certainty is not achievable, the engine says so explicitly rather than guessing.

How we hit 99%+: the 11-step verification engine. Every address runs through eleven distinct checks — syntax, domain DNS, MX records, SMTP handshake, mailbox existence, catch-all detection, disposable provider check, role-account detection, spam-trap detection, inbox-full detection, and disabled-account detection. No shortcuts, no "quick modes" that skip the SMTP handshake. The depth of the chain is the accuracy.

We also route across multiple verification providers in parallel. If one provider returns unknown due to rate limiting or anti-spam quirks, the other often has a definitive answer — which keeps the unknown rate low and the overall accuracy high.

Automatic refunds when we can't give you an answer

Here is the commitment that actually has financial teeth: you never pay for an answer we could not produce.

When the engine cannot reach a definitive verdict — the server timed out, anti-spam blocked the check, the network refused to cooperate, whatever the cause — the result comes back as unknown and the credit is automatically refunded to your PAYG bucket. No support ticket. No "we will look into it." No manual claim process. The cron returns the credit the moment the job finishes.

In the bulk pipeline this also covers a related case: emails that could not be processed at all in a job (server unreachable for the entire window, network errors mid-batch). Those rows go into a separate unprocessed file you can re-upload later, and you are refunded for every one.

Most verification services charge for unknown results because it is profitable to. We chose not to — partly because it is the honest call, partly because making unknown cost-free means you can trust our unknown rate is real and not artificially low to inflate billable verifications.

See refunds and credit returns for the full refund matrix, including duplicate handling.

No emails ever sent to your contacts

Verification is passive — SMTP handshakes and DNS lookups, all server-to-server. The protocol allows us to ask "does this mailbox exist?" without actually sending any message. We say hello, ask the question, get the answer, close the connection. The recipient never sees anything in their inbox.

Some lower-tier services actually send a test email to verify the address. That is a terrible idea: it hits the recipient's inbox, triggers spam filters, hurts your sender reputation, and reveals to the recipient that they are being checked. We never do that. The 11-step chain runs entirely on protocol-level conversations that the recipient cannot see.

15-day automatic data deletion

Bulk uploads and verification results are deleted from our servers 15 days after the job completes. Not "we might delete them eventually" — automatically, by a scheduled cleanup function. Once the 15-day window closes, the data is gone from our database and our backups age out shortly after.

What gets deleted: the original list you uploaded and the per-address verification results. What stays: aggregate job metadata (job name, total count, success rate) so you can see your historical activity in the dashboard. The raw addresses, the per-row results, and the downloadable files all disappear at the 15-day mark.

Practical implication: download anything you need within 15 days. The dashboard surfaces this deadline on the Uploads & Results page, but if you miss it, the data is genuinely unrecoverable — even support cannot pull it back. See how we protect your data for the full retention story.

No data resale, no list sharing, no AI training

Your data is yours. We do not sell email lists, we do not share them with third parties, and we do not train models on them. Our business model is selling verifications — there is no revenue path that involves doing anything else with your data, and no plan to start.

Provider routing aside (when we hand an address to a verification provider to check, that is the provider's purpose), no human at Valid Email Checker reads your list, no analytics tool aggregates it, no product feature relies on retaining it beyond the 15-day window.

What "accuracy" actually covers

Accuracy here is about whether the address exists and is deliverable at the moment of verification. It is not a guarantee that every email will arrive in the recipient's primary inbox once you send. Deliverability after the fact depends on factors outside our scope:

• Your sending domain reputation (SPF, DKIM, DMARC configuration).
• Your IP reputation and warm-up history.
• Your email content (spam-trigger language, suspicious links, image-only content).
• The recipient ISP's policies on the day.
• Whether the recipient hit "spam" on a previous campaign from you.
• Whether the mailbox was active at verification time but got deactivated before you sent.

Those are real factors and they matter, but they are not about whether the email is real — they are about how your sending infrastructure interacts with theirs. Verification fixes the "does this address exist" problem. The rest is your deliverability stack.

Why these specific commitments

Verification services traditionally hide behind soft marketing language — "up to 99% accuracy", "industry-leading deliverability", "best-in-class". None of that is verifiable from the outside. We took a different approach: pick a small number of specific, code-backed commitments and document exactly how each one is implemented.

• 99%+ accuracy is delivered by the 11-step chain you can read about in how verification works.
• Automatic Unknown refunds are visible in your credit history — every unknown result generates a matching refund row.
• 15-day retention is enforced by a scheduled cleanup function, not by a promise.
• No test emails is enforced by the verification engine literally not having that capability — there is no path in the code where a real message gets sent.
• No data resale is contractual and operational; no internal tool aggregates customer lists.

Specific commitments, real implementations. If we ever break one of these in code, you can hold us to it.

How to act on this guarantee

Most of what is above runs automatically. The few things that involve action on your part:

• For unknown results — credits return automatically; no claim needed. Check your credit history if you want to see the refund entries.
• For unprocessed bulk emails — download the separate unprocessed file from your job and re-upload later. The credits for those rows are already back in your balance.
• For the 15-day retention — download anything you need within the window. Set a calendar reminder if you have a long-running pipeline.
• For deliverability beyond verification — set up SPF, DKIM, DMARC properly. We have a primer on data protection that covers the basics.

Common questions

If I get an Unknown result, am I billed?

No. The credit is automatically returned to your PAYG bucket the moment the job completes. You can verify this in the credit-history log — every unknown result produces a matching refund entry.

If I get an Invalid result, do I get a refund?

No. invalid is a successful verification with a negative answer — the engine confirmed the mailbox does not exist. Refunds only apply when we could not produce an answer at all (unknown).

Why don't you also offer a bounce-rate guarantee?

Because bounce rate after you send depends on factors well outside our scope — your sending domain reputation, content, IP warm-up, recipient ISP policy on the day. Promising a bounce-rate number would mean either (a) inflating the promise with assumptions we cannot enforce or (b) carving out so many exceptions the guarantee becomes meaningless. We chose to commit to what we can actually back: the engine's accuracy on whether the address exists, and the Unknown auto-refund.

What if I think my list verified poorly?

Email support@validemailchecker.com with the verification task ID (visible in your dashboard) and what you observed. We can re-run a sample through the engine to diagnose. Credit adjustments are case-by-case for genuine engine errors; see refunds and credit returns for the cash-refund cases.

Next steps