Lead data and prospecting

Check email domains, domain authority and links in Voila Norbert

Run the emails you find in Voila Norbert through a domain check and sort them into reachable, risky and role-based groups before outreach.

Why the data matters in Voila Norbert

Finding an email is only the first step in outreach. The address Voila Norbert returns can still sit on a domain that is disposable or that receives mail only at a generic role mailbox, and a campaign that treats every found address alike spends send reputation on the ones that were never going to reply.

What LookValid checks

LookValid checks for Voila Norbert
Product	What it does here	Credits
Email Domain Check	Returns a good, risky or undeliverable signal for the domain of each found address, with MX, SPF and DMARC findings. The mailbox itself is never contacted. Marks free providers and role mailboxes so named work addresses can be placed first in a sequence.	1 credit per address checked
Domain Authority	Gives a 0 to 100 link-graph score for the company domain, to rank which accounts to contact first. It is an open-data score, not Moz or Semrush authority.	10 credits per domain found in the rank data (an unranked domain is free)
Link Safety Check	Checks the domain of a prospect website against a list of reported malicious domains, to remove obvious problems from a list.	1 credit per URL checked (a check that cannot run is free)

Connect it in four steps

Sign up for LookValid and get a key from the API keys area of the dashboard.
Export LOOKVALID_API_KEY in the shell or cron entry that runs check_norbert_email, so the saved list does not contain it.
Run the script on each email in the file saved with the Export option of the Prospecting tab or the Contacts tab: a null line means the lookup found nothing and the address stays as it was, and a failure prints the error code and fix and stops.
Merge signal, role and disposable back onto the list by email and keep the rows with a good signal. To load them into Sequences, use a CSV with a header row, one email per row, no line breaks inside cells and a size of 1 MB or less.

A shell job that reads the emails of a contact list saved with the Export option in Voila Norbert, and prints one check result for each. The call is POST https://YOUR_API_HOST/v1/email-domain-check and costs 1 credit per address checked.

check_norbert_email.sh

1#!/bin/sh
2# Usage: check_norbert_email.sh <value>
3set -eu
4jq -n --arg value "$1" '{"email": $value}' \
5  | curl --fail-with-body -sS -X POST "https://YOUR_API_HOST/v1/email-domain-check" \
6      -H "Authorization: Bearer $LOOKVALID_API_KEY" \
7      -H "Content-Type: application/json" \
8      -d @- \
9  | jq 'if .error then ((.error.code + ": " + .error.fix + "\n") | halt_error(1)) elif .found then {"signal": .data.deliverability_signal, "role": .data.role_account, "disposable": .data.disposable} else null end'

Where each response field goes in Voila Norbert
Response field	Goes into
data.deliverability_signal	signal
data.role_account	role
data.disposable	disposable

The recipe returns nothing when the lookup finds nothing, which costs no credits for this product, and stops with the error code and fix on a failed request.

Without code

If you prefer no script, an automation platform with a generic HTTP request step does the job without a dedicated app. Open the CSV that Export produced in a sheet, and for each row the HTTP step posts the address to the LookValid endpoint and the next step writes the signal beside it.

REST and MCPOne shared credit balance

Questions

What does it cost for a list of 500 emails?

Five hundred email-domain-check lookups at the rate on the pricing page. Dropping duplicates and addresses on the same domain you already checked saves credits.

Does it check the address or only the domain?

The domain and address pattern. It never contacts a mail server, so it cannot confirm that one mailbox is real.

Voila Norbert already verifies emails. Why run this too?

Norbert describes its Verify as opening a connection to the mail server and spotting catch-all domains. LookValid reads the domain records and address pattern instead, so the two give separate readings of the same list.

Where does the key go?

In the LOOKVALID_API_KEY environment variable of the machine running the job.

Sources

VoilaNorbert Help, Can I export my contact list? https://docs.voilanorbert.com/article/88-can-i-export-my-contact-list, read 2026-10-18
VoilaNorbert Help, How do I format my CSV file for importing prospects? https://docs.voilanorbert.com/article/107-how-do-i-format-my-csv-file-for-importing-prospects, read 2026-10-18
VoilaNorbert Help, What do you check for when verifying emails? https://docs.voilanorbert.com/article/56-what-do-you-check-for-when-verifying-emails, read 2026-10-18
LookValid API reference: Email Domain Check https://lookvalid.com/docs/api/email-domain-check, read 2026-10-18

LookValid is run by Meralume Labs. It is not connected to, endorsed by or a partner of any company or product named on this page, and every product name belongs to its owner.

LookValid bills every lookup in credits from one shared balance, so the same key works for each check above.

See Email Domain Check