Free Email and B2B Data Tools

Tools for sales and marketing teams. The live ones need no signup: 25 DNS checks a day, and 2 mailbox or person lookups every 30 days. The rest need a Clu account.

21 tools

21 tools, from an MX lookup to a CRM cleanup ROI model2 seconds for a typical live check

10,000+ users, from founders to full sales teams

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Start from what you already have

Each tool takes one thing you already have and gives back one answer. Pick the row that matches what is in front of you (an address, a name, a list, a domain, a draft, a phone number) or the number you need for a business case.

You have an email address and want to know who is behind it
Free Reverse Email Lookup and Email Extractor.
Start from the address and work back to the person, the company and the public profile.
You have a name and a company but not the address
Email Finder, Email Format Finder, Email Permutator, LinkedIn Email Finder and B2B Contact Finder.
Work out the pattern the company uses, build the likely addresses, then check them before you send.
You already have the addresses and need to know which ones will bounce
Free Email Verifier, Email Syntax Validator and Email List Cleaner.
Check the syntax first (instant, runs in your browser), then the live lookup, then the whole list at once.
You want to know whether the mail will land
MX Lookup Tool, Free Domain Validator, Free Email Blacklist Checker and Cold Email Spam Checker.
Whether mail lands depends on the sending domain and the message. Check both before you scale volume.
You have the address and still have to write the email
AI Cold Email Generator and Email Signature Generator.
Draft variants to react to, and a signature block that renders the same in Gmail and Outlook.
You have a phone number
Phone Validator.
Normalize it to E.164 and check it against its country's numbering plan before a rep calls it.
You need a number, for a plan or for a business case
TAM Calculator, ICP Fit Score Calculator, Data Quality Score Calculator and CRM Cleanup ROI Calculator.
Size the market, score the fit, grade the data you already hold, and price what cleaning it is worth.

Every tool

Validators check that something is real. Analyzers find or read what is already public. Calculators put a number on your data. Each runs in the browser or against a live lookup, and answers in seconds.

Email Format Finder
Find the email format behind any address with Clu, then get the verified email itself. It looks up the person across 25+ providers, so you stop guessing at first.last@ or flast@.name + companyverified emailInside CluAnalyzerAccount required
Data Quality Score Calculator
A data quality score grades your CRM on numbers you can pull yourself: bounce rate, duplicate rate and the age of your records. Clu verifies, dedupes and enriches the records behind that score.Inside CluCalculatorAccount required
CRM Cleanup ROI Calculator
Work out what bad CRM data costs your business and what cleaning it would be worth. Clu verifies and enriches the records so your reps stop fixing them by hand.Inside CluCalculatorAccount required
Email Syntax Validator
Email syntax is the set of rules that decides whether an address is well formed. Learn what RFC 5322 allows and which typos to catch, then check the mailbox itself with Clu.Inside CluValidatorAccount required
TAM Calculator
TAM is the full market your product could sell into. Learn how to estimate TAM, SAM and SOM yourself, then use Clu People Search to find the decision makers in that market.Inside CluCalculatorAccount required
Free Email Verifier
Check whether a mailbox is real before you send. Clu runs an SMTP mailbox check with catch-all detection, free for 2 checks per IP every 30 days, then half a credit per email inside a workspace.emailmailbox statusLive lookupValidator2 / 30 days
Free Domain Validator
Live MX, SPF, DMARC and NS lookups for any domain. Find the setup problem before your first send.domainNS, MX, SPF, DMARCLive lookupValidator25 / day
Free Reverse Email Lookup
To find out who owns an email address, enter it above and Clu looks it up in B2B contact data. When it finds the person, you get their name, company, job title, city and country, with the phone number and LinkedIn URL shown masked. It's free for 2 lookups per IP every 30 days, and it isn't available on VPNs or hosted networks.emailperson, company, locationLive lookupAnalyzer2 / 30 days
B2B Contact Finder
Find business contacts by name and company in Clu. It looks each person up across 25+ providers and verifies the email before you get it.name + companyverified emailInside CluAnalyzerAccount required
Email Finder
An email finder takes a person's name and company and returns their work email. Clu checks 25+ data providers in sequence, stops at the first deliverable address and verifies it before you get it, at 1 credit per verified email. A miss costs nothing.name + companyverified emailInside CluAnalyzerAccount required
Phone Validator
A phone validator checks whether a number could be real before anyone calls it: it normalizes the number to E.164, identifies the country and numbering plan, and rejects it if the length or prefix is impossible. You can run these checks yourself from the rules below. Clu finds phone numbers across 25+ providers, at 10 credits per number found.Inside CluValidatorAccount required
ICP Fit Score Calculator
An ICP fit score shows how closely an account matches your Ideal Customer Profile on firmographics, technographics and behavior. Learn how to build one, and let Clu score your leads.Inside CluCalculatorAccount required
Email Permutator
An email permutator turns a person's name and company domain into every likely address: jane.doe@acme.com, jdoe@acme.com, jane@acme.com, doej@acme.com and roughly twenty more. Usually only one is a live mailbox, and the rest bounce. Clu skips the guessing: it looks the person up across 25+ providers and returns the one verified email.Inside CluAnalyzerAccount required
Cold Email Spam Checker
Learn what routes a cold email to spam before you send it: trigger words, formatting and links, plus the bounce rate that matters more than any of them. Clu verifies the list so your copy reaches real mailboxes.Inside CluAnalyzerAccount required
Free Email Blacklist Checker
Check whether your domain or sending IP is on a known email blacklist. Tests against 9 major DNS blocklists (Spamhaus, SpamCop, Barracuda, and more) in seconds, with plain-English results.domain, email or IPblocklist statusLive lookupValidator25 / day
MX Lookup Tool
An MX lookup shows which mail servers receive email for a domain. Enter a domain or an email address and this free tool returns the MX records ranked by priority, names the provider behind them (Google Workspace, Microsoft 365, Zoho, Proofpoint and more), and checks whether an SPF record exists. 25 lookups per IP per day, no signup.domainMX recordsLive lookupAnalyzer25 / day
AI Cold Email Generator
Learn how to write a cold email with three proven frameworks: AIDA, Problem-Agitate-Solve and a short pattern interrupt. Clu finds and verifies the person to send it to.Inside CluAnalyzerAccount required
Email Signature Generator
What a professional email signature should include, and how to add one to Gmail, Outlook and Apple Mail. Keep it to your name, title, company, phone and one or two links.Inside CluAnalyzerAccount required
LinkedIn Email Finder
Paste a LinkedIn profile URL and this tool looks the person up and returns their email, name, company and job title, with the phone number shown masked. It's free for 2 lookups per IP every 30 days and isn't available on VPNs or hosted networks. The free lookup checks one provider, so a result may be out of date and some profiles return nothing.profile URLemail, title, companyLive lookupAnalyzer2 / 30 days
Email Extractor
Enter a website URL and this free email extractor fetches the page, pulls every email address out of the HTML, removes duplicates, and hands you a list you can copy or download as a CSV. Paste raw text or HTML instead and the same scan runs entirely in your browser. No signup, no extension.URL or textevery email on itLive lookupAnalyzer100 site scans / day
Email List Cleaner
Email list cleaning removes duplicates, invalid syntax, role-based addresses, typo domains like gmial.com and disposable inboxes before you send. Do it yourself in a spreadsheet, then let Clu check the mailboxes at half a credit per email.Inside CluValidatorAccount required

From free to $49 a seat

The live tools are free. The trial is 14 days of Pro, free. Each step below, from a one-off lookup to a full workload, comes with its number.

You are here25 a dayPer IP, per tool, on the 3 tools that make a live DNS lookup. The email extractor gets 100 site scans a day, and the mailbox and person lookups get 2 every 30 days, off VPNs and hosted networks.
50 creditsA month on the $0 Free plan after the trial, for up to 3 seats. Search costs no credits on any plan.
14 daysOf Pro, free, for every new workspace: 250 credits, 3 seats, agents, Sequences and Clu in Slack. Every Pro feature is on.
$49Per seat a month for Starter when the trial ends, or 25% less billed annually. Every seat adds its credits to one shared wallet.

Do the same jobs on a whole list

Describe your buyer in one sentence and Clu runs the search, enriches the list, validates it and gets it ready for your CRM in under five minutes. It adds bulk verification and two-way CRM sync.

Start free trial See pricing

98% verified work emails and 85% phone numbers on our 500-lead benchmark, across 25+ providers.

Data leaders, Series C+25

Hey Alex, ready to get started?

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Find peopleFind companies

Alex Kim9:41 AM

Find Heads of Data or Analytics, 2-5 years in the role, at Series C+ software companies with 201-1,000 people that raised in the last 12 months. US or Canada. Skip HubSpot customers. Verify their emails.

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Clu

16 steps · 1m 58s

25 leads, 24 verified emails. One is a catch-all, so I marked it risky.

Ask Clu to help (type / for skills, @ for agents and lists)

Data leaders, Series C+25 leadsActions

NameCompanyPrimary EmailStatus