Buyer guide · SimpleVerifier Team
Catch-all email verification
A catch-all domain's mail server accepts every address, real or made up, so no verifier can confirm the mailbox by asking it. SimpleVerifier detects catch-all domains, keeps those rows risky (never valid), and grades each one higher, medium or lower likelihood from name-format evidence, with the reasons. The first 100 checks are free; plans start at $9 a month.
Catch-all addresses are common in B2B lists, because many company mail servers accept everything and sort it out later. Sending to them blind is how a clean-looking list still bounces: the server said yes at the door, then bounced the message once it was inside.
Some verifiers mark catch-all rows valid, or sell a separate score for them. We keep the row risky and show our evidence, so you choose what to send. The method, the signals that worked and the ones that did not are published on catch-all scoring, back-tested on 82,853 addresses.
Test it on a real address first
Type any address. It gets the same check the paid plans run: syntax, the domain’s mail servers and, where the provider allows it, a live mailbox check. Nothing is sent to the address.
Five checks a minute, no account needed. Nothing is sent to the address — we ask its mail server whether the mailbox exists, then disconnect.
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How SimpleVerifier grades a catch-all address
Higher likelihood: the address uses the same name format as addresses already confirmed on that domain (for example first.last next to a confirmed first.last), or the format most of the list uses for that domain.
Medium: weaker or mixed evidence, such as a single-word name (anna@) next to confirmed single-word addresses, or no evidence either way. Lower: one of several spellings of the same name on that domain (anna.lee, a.lee, alee), a format that differs from the domain's confirmed one, or test@ and noreply@, which nobody reads.
Each row comes back with the grade, plain-sentence reasons and stable signal codes, in the CSV, the API and the MCP server. The status stays risky and every reason list ends with "Still unconfirmed". The grade opens no extra mail connection.
The mail host, SPF and DMARC records and server response timing were tested and did not separate real from non-existent addresses in our data, so they do not move the grade. The catch-all scoring page has the numbers.
What a catch-all result costs
On Starter ($9, 2,500 emails a month) and Growth ($19, 10,000 emails a month) a catch-all row counts as one check, because it is checked and graded. Addresses we can't check and duplicates don't count. Pro, Business and Agency have no per-email charge: Pro is $29.99 a month, never cut off: the first 100,000 emails a month run at full speed, then big lists run slower.
How other vendors bill catch-all results, from their own pages: ZeroBounce, read 30 Oct 2026: Charged as a normal credit. The FAQ lists only unknown results and duplicate removal as the cases it does not charge, and catch-all is not on that list. MillionVerifier, read 30 Oct 2026: Credits come back on the same goodwill rule as unknown results, and its homepage says catch-all verification is included at no extra cost. Reoon, read 30 Oct 2026: Charged. Its FAQ counts a catch-all result as a successful verification, which costs one credit (anything except unknown).
How to send to catch-all addresses
Keep them out of the main campaign. Send higher-likelihood rows first, in small batches, and watch hard bounces; drop lower-likelihood rows, most of which are guessed spellings. The list download can return confirmed rows only, confirmed plus higher-likelihood catch-alls, or confirmed plus every catch-all except lower.
Through the API, the same grade comes back in catch_all_confidence with catch_all_reasons and catch_all_signals, on the same call as the mailbox check. See the API reference.
When another verifier is the better pick for catch-alls
- You want a vendor that turns part of your catch-alls into a definite valid or invalid. MillionVerifier says it resolves part of them with a proprietary method; we do not, because the server's answer cannot confirm them.
- You want catch-all credits handed back. MillionVerifier's help center says it adds back credits used on unknown and catch-all results; on our flat plans there is nothing to hand back.
- You want a numeric score on every result. ZeroBounce sells AI scoring credits and Reoon returns a 0 to 100 score; ours is a three-level grade with written reasons.
Common questions
- Can a catch-all email address be verified?
- Not by asking the mail server, because it accepts every address. A verifier can detect that the domain is catch-all and weigh other evidence. SimpleVerifier keeps these rows risky and grades them higher, medium or lower likelihood with the reasons.
- Should I send to catch-all emails?
- Not mixed into the main send. Send higher-likelihood rows in small batches, watch bounces, and drop lower-likelihood rows.
- Do email verifiers charge for catch-all results?
- Most count them as a normal check. ZeroBounce, read 30 Oct 2026: Charged as a normal credit. The FAQ lists only unknown results and duplicate removal as the cases it does not charge, and catch-all is not on that list. MillionVerifier, read 30 Oct 2026: Credits come back on the same goodwill rule as unknown results, and its homepage says catch-all verification is included at no extra cost. Reoon, read 30 Oct 2026: Charged. Its FAQ counts a catch-all result as a successful verification, which costs one credit (anything except unknown). On SimpleVerifier Starter and Growth a catch-all counts as one check; Pro and up have no per-email charge.
- Why does SimpleVerifier never mark a catch-all address valid?
- Because the server's yes means nothing on a catch-all domain. Marking it valid would hide the risk from you; the grade tells you how likely it is instead.
Grade your catch-alls
Pro is $29.99 a month and never cuts you off: the first 100,000 emails a month run at full speed, then big lists run slower. CSV uploads, the API (10,000 calls a month, then $1.50 per 1,000), the Google Sheets add-on and the email finder are included, and you can cancel any time. For smaller volumes, Starter is $9 a month for 2,500 emails a month and Growth $19 a month for 10,000 emails a month.
The first 100 email checks are free with a Google sign-in, no card, on the same engine the paid plans use.