Email verification results explained: sort any verifier's file into send, retest and remove
Email verification results come in four kinds whatever the vendor calls them: valid (send), invalid (remove), catch-all or accept-all (unconfirmed) and unknown (no answer). Drop your verifier's results file here and every row is sorted into send, retest or remove by its status, with a CSV for each and a live recheck of 10 unconfirmed addresses.
By SimpleVerifier Team · Last updated
How do I read email verification results?
- Download the full results file from your verifier, with its status or result column (ZeroBounce
status, NeverBounceresult, Kickboxresultand so on). - Drop it in and press Sort the results. The status column is found by its header; every other column is kept.
- Read the table of statuses in your file, each marked Safe to send, Unconfirmed or Remove. Statuses the tool doesn't know are listed, never guessed.
- Download safe-to-send, unconfirmed and the removed rows as three CSVs.
- The unconfirmed rows go first in a live recheck of 10. Sign in with Google to recheck the rest with 100 free email checks.
What do ZeroBounce status codes mean?
ZeroBounce's status codes are valid, invalid, catch-all, unknown, spamtrap, abuse and do_not_mail, with a sub_status giving the detail (for example do_not_mail with role_based or disposable). Send valid; remove invalid, spamtrap, abuse and do_not_mail; treat catch-all and unknown as unconfirmed.
That's how this tool sorts them. Note that do_not_mail mixes several reasons: a role-based info@ at a small company may be someone you'd still write to by hand. The removed-rows file keeps the sub-status column so you can make that call.
What is the difference between catch-all and unknown results?
Catch-all (also called accept-all, accept_all, catchall or ok_for_all) means the verifier reached the mail server and the server accepted a made-up address too, so no address at that domain can be confirmed. Unknown means the verifier never got a usable answer: a timeout, greylisting or a refused connection.
They call for different moves. Unknown is a failed check, worth repeating a day or two later, ideally from a different checking server, which is what the recheck here does. Catch-all won't change on a recheck; send those rows separately in small batches, or leave them out. The vendor-by-vendor table is in email verification statuses explained.
Should I send to risky or catch-all emails?
Only deliberately. A catch-all domain accepts mail for real and made-up users alike, and some of those messages will bounce later or go nowhere. If the addresses matter, send them as their own small campaign after the valid ones, watch the bounce rate, and stop if it climbs. If you're warming up a new domain, leave them out until it has a history.
Kickbox and Bouncer file catch-all under risky, so a "risky" count from them is mostly catch-all. Disposable addresses, which have working mailboxes nobody reads, are removed here whichever vendor flagged them. More in should you send to catch-all emails.
How do different verifiers name the same result?
| Vendor | Send | Unconfirmed | Remove |
|---|---|---|---|
| ZeroBounce | valid | catch-all, unknown | invalid, spamtrap, abuse, do_not_mail |
| NeverBounce | valid | catchall, unknown | invalid, disposable |
| Kickbox | deliverable | risky, unknown | undeliverable |
| Hunter | valid | accept_all, unknown, webmail | invalid, disposable |
| EmailListVerify | ok | ok_for_all, unknown | email_disabled, dead_server, invalid_mx, disposable, spamtrap |
Labels from each vendor's API documentation, linked under Sources. Hunter's webmail marks a free webmail address; it's sorted as unconfirmed here.
Who uses this tool, and for what?
- Teams switching verifiers
- Make an old results file usable without re-paying for the rows that already have a clear answer.
- Cold emailers
- Turn a results file into an upload-ready list and a separate catch-all batch in one step.
- Agencies
- Normalise results from whichever verifier a client used into the same three files, every time.
What can’t this tool tell you?
- The sort follows your verifier's status; it doesn't re-verify every row (only the 10-address recheck and the free checks do).
- Numeric status codes (some vendors return numbers) aren't mapped; they're listed as not recognised.
- A status that means different things at different vendors is sorted the cautious way (unconfirmed, not send).
- The browser check covers the first 5,000 rows of a file.
Common questions
- What does catch-all mean in ZeroBounce?
- The domain's mail server accepts any address, real or made up, so ZeroBounce can't confirm the mailbox. It isn't a bad address, just an unconfirmed one; send catch-all rows separately and in small batches.
- What does do_not_mail mean in ZeroBounce?
- A valid-looking address ZeroBounce advises against mailing, with a sub-status giving the reason, such as role_based, disposable or toxic. Most should come off a marketing list; role addresses at small companies are a judgement call.
- What does unknown mean in email verification?
- The verifier didn't get a usable answer from the mail server, because of a timeout, greylisting or a refused connection. Recheck unknown addresses a day or two later rather than deleting them straight away.
- What are NeverBounce result codes?
- valid, invalid, disposable, catchall and unknown. Send valid, remove invalid and disposable, and treat catchall and unknown as unconfirmed.
Sources
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.