Free email domain checker — business vs. personal
Paste a list and split business emails from Gmail, Yahoo, and other free providers.
Paste email addresses or domains — one per line, or a whole CSV column — and each one is classified as business, free provider, or invalid against the 4,768-domain free email list that HubSpot forms block with “Block free email providers”. Role mailboxes like info@ and sales@ are flagged too. The check runs in your browser, so nothing you paste is uploaded; copy the business addresses or download the results as CSV. The same rule is a free UnifAPI endpoint for your forms, CRM jobs, and agents.
Give this to your agent
read https://unifapi.com/tools/free-email-domain-checker/index.md and check which of my email addresses use free email providers and return only the business onesand let it take it from there.
Free · no API key · read-only. Works in any agent that can open a link.
Built on the UnifAPI gateway
Every result above is one API call against the same live public-data surface that UnifAPI Skills use. Agents can call the same data through MCP when a workflow needs evidence.
Questions about this tool
What counts as a free email domain?
A domain anyone can sign up on for a personal mailbox: Gmail, Yahoo, Outlook and Hotmail, iCloud, AOL, GMX, Mail.ru, QQ, and thousands of regional and legacy providers. The checker uses the 4,768-domain list that HubSpot forms block with “Block free email providers”, so a free result here predicts what that setting would do with the same address.
Does “business” mean the email address is real?
No. Business means the syntax is valid and the domain is not on the free-provider list. The checker does not look up MX records, contact the mail server, or detect disposable inboxes, so a business address can still bounce. Use it to sort a list, not to verify deliverability.
Are the emails I paste uploaded anywhere?
No. The domain list loads into the page and every check runs in your browser; the addresses you paste are not sent to UnifAPI. Because nothing runs on a server, there is no rate limit — paste up to 10,000 entries at once.
Why are info@ and sales@ flagged?
They are role mailboxes: shared inboxes for a team or function rather than a person. They are still business addresses, so the result stays business, but many teams score and route them differently from a named contact.
Does it catch subdomains and newer providers?
Matching is exact, so a company subdomain is not marked free just because a parent domain is on the list. The list also misses some newer providers — proton.me, tuta.com, and hey.com are not on it — so keep your own blocklist for those if they matter to your forms.
Is there a free email filter API?
Yes. GET /email/check classifies one address, POST /email/check/batch takes up to 1,000 per call, GET /email/domains/{domain} checks a domain, and GET /email/free-domains pages through the whole list. Every call costs 0 credits with a UnifAPI workspace key, and agents can call the same endpoints through MCP.
Use the same data in your own agent.
Add UnifAPI once, then ask your assistant to fetch live public data with the same per-record pricing.