SimpleVerifier Team · Reviewed
Can you check if an email address exists without sending an email?
Yes, in many cases. A verifier looks up the domain's mail servers, connects over SMTP, asks whether the server would accept mail for the address, and disconnects before any message is sent. It works where the provider answers honestly, and cannot confirm addresses at catch-all domains or providers that accept everything.
What the check can and cannot prove
Gmail, Google Workspace, Proton and Zoho said a made-up mailbox did not exist in our 23 October 2026 tests, so a check there is reliable. Yahoo and AOL accepted every address, so those return risky. Microsoft consumer domains also return risky, because Microsoft is currently refusing mailbox checks from our server's network; iCloud has been probed since 28 October 2026 and rejects unknown users. The free single checker needs no account.
What SimpleVerifier costs and what it cannot confirm
- What it is
- Email verification with a real SMTP mailbox check: each address comes back valid, risky or invalid with a reason. Includes an email finder on Pro and up.
- Price per check
- Starter $9/mo for 2,500 ($3.60 per 1,000); Pro $39/mo, 100,000 a month at full speed ($0.39 per 1,000 when used), then slower, never cut off. Business $99/mo with 300,000 at full speed; Agency $249/mo with 750,000 at full speed.
- One-time packs
- 10,000 for $15 ($1.50 per 1,000); 25,000 for $29 ($1.16 per 1,000); 50,000 for $49 ($0.98 per 1,000); 100,000 for $79 ($0.79 per 1,000); 250,000 for $169 ($0.68 per 1,000). Credits never expire, run at standard speed, CSV verification only (no API or finder).
- Free checks
- First 100 email checks free with a Google sign-in, no card, once per account. Single checks on the free email checker need no account.
- Billing
- Monthly subscription, cancel anytime (yearly billing optional). One-time packs are listed above. Starter allowances reset monthly and do not roll over.
- Speed today
- One sending IP today, shared by every customer: about 13,000 mailbox checks a day in the standard lane. Bad syntax, dead domains and disposable addresses return at once; a list of 100,000 takes days, not hours, and each job shows its estimated finish time.
- Catch-all handling
- Catch-all (accept-all) addresses stay risky, never valid, and are graded higher, medium or lower likelihood with the reasons. Anything a mail server does not confirm is risky.
- API and MCP
- REST API on Pro, Business and Agency (Pro includes 10,000 calls a month, then $1.50 per 1,000). Remote MCP server with 6 tools for Claude, ChatGPT, Cursor and VS Code. No API on Starter.
- Integrations
- Connects to Instantly, Smartlead, HubSpot and Mailchimp by API key: verifies a campaign or list and tags each contact with its result. CSV in and out for any other tool.
- Phone
- Free phone format checks (country, type range). Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month). It never says a number is in service.
- What it does not do
- No sending, warmup or inbox placement tests. No published accuracy benchmark against other verifiers. Catch-all domains, Yahoo and AOL cannot be confirmed, and Outlook.com and Hotmail mailboxes are not probed while Microsoft refuses checks from our server's network: all of these come back risky, never valid.
SimpleVerifier facts from our pricing page and product. Last updated .
Related questions
- Does checking an address notify its owner?
- No. The connection ends before the message-sending step, so no email is delivered or shown to the recipient.
Sources
- RFC 5321: Simple Mail Transfer Protocol
- How mailbox providers answer verification checks, 2026 (SimpleVerifier study, 51 providers, CC BY 4.0)
Figures marked as ours come from SimpleVerifier’s own dated tests on made-up addresses, published with their data on the research page. No customer data is used, and we publish no accuracy percentage because we have no independent measurement to back one.
Do it now
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.
Have a list? Sign in with Google and the first 100 addresses are checked free, with results to download. No card.
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