Frequently asked questions

Every address runs through nine stages on your own PC: syntax & parsing, duplicates, your own rules, heuristics (disposable, role, free-provider, typo and placeholder detection), DNS mail routing, domain authentication (SPF, DMARC, MTA-STS, BIMI), six mail-server blocklists, a 20-signal spamtrap engine and, if you switch it on, SMTP mailbox probing.

Each address ends in exactly one of seven verdicts (passed, risky, invalid, unknown, filtered, duplicate or honeypot) with a score from 0 to 100, a reason code and a plain-English explanation. See every method.

No. The app verifies everything on your own computer. The only traffic it creates is the DNS lookups the checks need (and, if you enable probing, the SMTP conversations with mail servers). Your list, your results and your exports stay on your PC.

The one exception is a mailbox check you choose to run on the Dpunk probe server: only the addresses being checked are sent there, over an encrypted connection, and they are deleted within an hour.

Never. The SMTP prober asks the mail server about a recipient and hangs up before a message could start; it has no code path for sending mail at all.

Because a check could not finish: a DNS timeout, greylisting, a blocked port 25 or a temporary failure. The rule is simple: an inconclusive check never becomes a verdict. A false “invalid” would make you delete a real customer, so these addresses are marked unknown. Re-check them later; do not delete them.

It is optional, off by default and part of the Pro and Enterprise plans. Most list problems are caught by the DNS, blocklist, heuristic and spamtrap stages. Probing asks whether an exact mailbox exists.

The easiest way is the Dpunk probe server: turn probing on, keep that option selected, and the checks run from our server, so it works even when your network blocks port 25. It includes 10,000 a month on Pro and 50,000 a month on Enterprise.

You can also check from your own PC: that needs outbound port 25 (which most home connections block) or a mail server installed on the same PC (Enterprise). Your own mail account can also act as a relay (10 provider presets, port and encryption detected automatically), but a relay only gives real answers for the domains it hosts itself, such as your company’s own addresses. The Run test button tells you which works from your network.

A small server we run with outbound port 25 open, so mailbox checks (SMTP) work even when your internet provider blocks that port, as many do. It asks each mail server whether a mailbox exists and hangs up before any message could start, exactly like the app does.

Only the addresses you choose to check are sent to it, over an encrypted connection. They are deleted within an hour of the check; for a day the server keeps only a one-way hash, so the same address checked again is answered at once. Your list, your other results and your exports never leave your PC.

It includes 10,000 a month on Pro and 50,000 a month on Enterprise, shared by all your PCs and reset on the first day of each month, and 200 checks during the free trial. If you run out, the remaining mailbox checks show unknown and every other check still runs. The app shows how many are left on its SMTP tab.

Up to 1,000,000 rows per run on Pro and Enterprise, and up to 100,000 on Essential, from pasted text or a .txt, .csv or .tsv file. Results stream in live and you can pause, resume or stop at any time and keep what has been checked so far.

Windows 10 or 11 (64-bit) and an internet connection for the DNS lookups. It is a single EXE of about 12 MB with nothing to install. The window uses Microsoft Edge or Chrome in app mode and falls back to your default browser. Download details.

No tool can promise that, because trap operators do not publish their lists. The engine combines 989 known trap addresses and 327 trap and blocklist domains with 20 independent signals (naming, machine-made local parts, DNS routing and zone fingerprints). A score of 4 or more quarantines the address as honeypot, and every signal that fired is shown with its points so you can see why.

Yes, with Enterprise. --check a@b.com verifies addresses from the command line and prints JSON, and --file list.csv runs a headless batch that writes a verified CSV next to the input.

Verification is the same in every plan: all nine stages, the 20-signal spamtrap engine, the 989 known trap addresses and the six blocklists. The plans differ in what you can do around it:

• Essential: up to 100,000 rows per run; CSV and TXT exports; up to 24 parallel checks; 1 PC (Machine IDs); email support.
• Pro: everything in Essential, plus up to 1,000,000 rows per run; SMTP mailbox probing (direct + your own relay); 10,000 mailbox checks a month on the Dpunk probe server; JSON and ZIP exports; save snapshots; editable intel lists; 3 PCs (Machine IDs); priority email support.
• Enterprise: everything in Pro, plus 50,000 mailbox checks a month on the Dpunk probe server; command line automation (--check, --file); this computer's mail server (localhost mode); up to 128 parallel checks; 10 PCs (Machine IDs); priority support + onboarding call.

The plan is written into your license key, so the app turns on the right features offline. Compare the plans side by side.

Pay with crypto via Cryptomus: USDT, BTC, ETH, LTC, TRX and more. Your license key is issued automatically the moment the payment confirms. No waiting for a person to read an email.

As soon as the network confirms the payment. Your order page updates by itself, the key appears under Devices & keys in your account, and it is emailed to you. Confirmation time depends on the coin and network you choose.

If a payment arrives short, the order is marked underpaid and you can top it up from the same payment page. If you overpay, the order is still completed. For anything unusual, write to support@dpunkmade.com with your order number.

3 days with the Pro features on one PC, no payment needed: SMTP probing, up to 1,000,000 rows per run, JSON and ZIP exports, snapshots and editable lists. Create an account, verify your email, then open the app and choose Start 3-day free trial on its License screen. It signs in and activates by itself. One trial per email address and one per PC.

The app’s License screen shows a Machine ID like A1B2-C3D4-E5F6-7890. It is a fingerprint of that PC, and nothing about your computer leaves it. Each plan covers a number of PCs. Sign in inside the app on each PC and it is added to your account with its own key. You can also add a Machine ID by hand in your account.

Yes. If the old PC still works, click Deactivate this PC on its License screen, then sign in inside the app on the new PC. That is never counted. If the old PC was formatted, sold or broken, use Move to another PC in your account: up to 3 moves per 30 days, plus one Reset all PCs. Contact us if you need more.

Crypto payments are never charged automatically, so nothing is taken without you. We email you 7 days and 1 day before your term ends; renew from your account and the time is added to the end of your current term. Keys are renewed automatically for every registered PC, and the app picks up the new key at its daily check-in.

Yes. The new plan starts immediately and the unused days of your current term are credited pro-rata, converted at the new plan’s daily rate. New keys with the new plan’s features are issued for every registered PC right away, and the app picks them up at its daily check-in (or click Check for renewal now).

The app gives you a 3-day grace period. After that, starting a new verification needs a valid key, but everything else keeps working: your results, snapshots and exports stay available.

Yes, within 7 days of your first purchase if the app cannot run on your Windows PC. Crypto refunds are paid in USDT at the original USD value, minus network fees. Please try the free trial first. Read the refund policy.

You need a website account to start a trial or buy a plan, because your keys and devices are managed there. In the app you simply sign in with the same email and password to activate. After that the app works offline and checks in once a day when it can.