Business Contact Enrichment — Instantly Get Name, Title, Email, Phone & LinkedIn Profile
Bulk verify email quality, identify valid, business, and risky emails, and improve contact data quality and outreach results.
Email Verification Tool helps you verify email address quality — spotting invalid and high-risk mailboxes before you send sales emails, run marketing campaigns, or use customer data.
It verifies addresses in bulk, checking email validity, mailbox type, and risk status, and returns structured results you can use to filter for valid contacts and optimize your email lists.
Combined with CoreClaw's data collection, you can source business leads from Google Maps, LinkedIn, websites, and other channels, verify their email addresses before sending, and improve outreach efficiency while lowering bounce risk.
Unverified email data typically contains:
These low-quality addresses can cause:
With Email Verification, you filter out low-quality contacts before you send — so your email marketing and sales development perform better.
| Field | What it tells you |
|---|---|
email | The address that was checked |
isValidFormat | Whether the address format is valid |
isBusinessEmail | Whether it is classified as a business email |
isCompanyEmail | Whether it is classified as a company email |
isWebmail | Whether it uses a free webmail provider |
isDisposable | Whether it comes from a disposable email provider |
isCatchall | Whether the domain appears to accept catch-all mail |
isGreylist | Whether the mailbox or server appears to use greylisting |
isGibberish | Whether the local part looks like gibberish |
sendStatus | Final sendability status from the verification service |
To help you verify email at scale, CoreClaw provides:
The list of email addresses to verify — one address per line. This is the tool's only input.
Recommended: provide well-formed, real addresses and mix sources (a business mailbox, a webmail address) so you can see the type classification and risk flags work across cases.
Avoid addresses with stray spaces, no domain suffix, or a broken @ — those are rejected by the local format check before any request is made, so they never reach the verification service.
Format: one address per line, shaped like name@example.com. The local part and the domain must not start or end with a dot, and must not contain ..; surrounding whitespace is trimmed automatically.
The snippet below is the run input (the input.parameters.custom payload):
Results appear in a table with the 10 columns described above. You can sort, group, and filter — for example, keep only rows where sendStatus is valid.
isValidFormat, sendStatus)isDisposable, isCatchall, isGreylist, isGibberish)isBusinessEmail, isCompanyEmail, isWebmail)sendStatus status
| Status | Meaning |
|---|---|
valid | The mailbox is valid and can receive email |
invalid | The mailbox is invalid and cannot receive email |
unknown | The status could not be determined |
You can filter based on the verification results to fit your business needs. For example:
valid mailboxes for sendingisDisposable)isBusinessEmail) for B2B salesFull output example:
How does it work?
You paste your list of email addresses and run it. The tool checks each address one by one and returns format validity, email type, risk flags, and a final sendability status — one row per address that you can filter, download, or import into your CRM. Everything runs automatically, so there's nothing manual to manage.
Can I verify a large batch at once?
Yes. The email input is an array — add one address per line. The run is split on the email field (concurrency), so the platform verifies addresses in parallel. The script itself has no built-in cap; the practical ceiling is your list size and whatever limits your verification service applies.
What happens to malformed addresses?
They are skipped locally before any request. The worker rejects addresses that don't match name@example.com, or whose local part or domain starts or ends with a dot or contains ... Skipped addresses are logged, not sent to the verification service.
What if the verification service fails or times out?
One bad request doesn't sink the run. A network error, a timeout (300 seconds), or an upstream error (code != 0) is recorded for that address, and the rest still get verified. If every request fails, the run produces no rows. For safety, the worker never logs the upstream URL, credentials, or raw response contents.
What do the result flags mean?
They are the verification service's judgment on each mailbox, so you can tell its type and quality at a glance: business or company mailbox, free webmail, disposable email, catch-all domain, greylisted or gibberish-looking address, and whether the format is valid. Use them alongside the status when filtering to separate good contacts from risky addresses.
Does it send test emails?
No. The worker only issues a GET request to the configured verification endpoint with each address as a query parameter. It does not send mail or trigger signups itself.
Can I integrate it with other apps?
Yes. Results export in 8 formats — CSV, JSON, JSONL, XLSX, XLS, XML, HTML, RSS — and the platform supports webhook callbacks, MCP, and n8n workflows.
Can I use it as an API?
Yes. Use the CoreClaw REST API to run it programmatically.
The base URL is https://openapi.coreclaw.com, all paths start with /api/v2, and you authenticate with Authorization: Bearer YOUR_API_KEY (the legacy api-key header and ?token= query still work).
Typical flow:
GET /api/v2/workers/{workerId}/input-schema to fetch the input schema (or GET /api/v2/workers/{workerId} for full details). workerId is a slug or owner~name path; version defaults to latest.POST /api/v2/workers/{workerId}/runs to start a run — pass is_async, and put the scraper input in input.parameters.custom. Set a callback_url to receive a callback instead of polling.data.run_slug.GET /api/v2/worker-runs/{runId} to check status (use the run_slug as {runId}).GET /api/v2/worker-runs/{runId}/result for the result, or /result/export for a file export.Is verifying email addresses legal?
Verifying addresses you legitimately own or collected with consent is common practice. Make sure you comply with the privacy and anti-spam regulations that apply to you (e.g. GDPR, CAN-SPAM) and with the terms of the verification service you use.
Found a bug, or want a new output field? We'd love to hear from you — reach out at support@coreclaw.com.