SimpleVerifier Team · Reviewed
How do I choose an email verifier?
Check five things: whether it does a real SMTP mailbox check, how it labels addresses it cannot confirm, whether it charges for unknowns, how the pricing fits your monthly volume, and what happens to your data. Then test it on a small file of addresses whose answers you already know.
The checklist
Send these to any vendor, or read them off its pricing page.
- Real mailbox check: does it connect to the recipient's mail server, or only check syntax and MX?
- Unconfirmable addresses: does it say risky or unknown, or guess valid?
- Cost of unknowns: are they charged, refunded or free?
- Credits: do they expire, and do monthly credits roll over?
- Price at your volume, including re-checks, and any file size or speed limits.
- Integrations or API for the tools you use.
- Data: retention period, a data processing agreement and a subprocessor list.
A one-hour test
Build a file with a fabricated address at a provider that rejects unknown mailboxes, your own real address, a broken address, a disposable address, a domain with no mail server and a role address. Any tool you pay for should get all of them right. Run the same file through two vendors and read the disagreements, which cluster in the rows that matter.
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
- Capacity is shared by every customer: plan on about 13,000 mailbox checks a day in the standard lane (more when the queue is quiet). 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.
- Privacy and GDPR
- Data processing agreement countersigned on request (/dpa). Results files deleted 7 days after a list is submitted; confirmed results cached by address for 14 days. Lists are not used for marketing, sold or shared. Verification runs on a US server. No GDPR certification is claimed.
- 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
- Should I trust accuracy percentages?
- Be careful. Headline percentages are rarely defined or audited; test on addresses whose answers you know.
- Why do verifiers disagree on the same list?
- They treat uncertain cases differently, such as catch-alls and servers that would not answer. One may say risky where another guesses valid.
Sources
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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