SimpleVerifier Team · Reviewed
What is the best email verifier for cold email?
Pick on two things: how it treats catch-all and unconfirmable addresses, and whether results flow into your sequencer. SimpleVerifier connects to Instantly and Smartlead by API key and tags each lead valid, risky or invalid; Pro is $39 a month. Other tools fit better in some cases, so test on a list you know first.
What matters for cold email
Cold senders are punished for bounces faster than newsletter senders, because new domains and inboxes have little reputation to spend.
- Catch-all handling: no verifier can confirm a mailbox on a catch-all domain, so look for a clear risky label and send those in small tested batches.
- An SMTP mailbox check, not just syntax and MX. Test with an address you invented at a real company domain; a real check returns invalid or risky.
- Integration with Instantly, Smartlead or lemlist, so you do not export and import by hand.
- A flat price if you re-verify every week, since re-checks add up on per-email billing.
Where another vendor may fit better
If you verify one list a quarter, a never-expire credit pack from another vendor can cost less. If you need a catch-all second pass sold separately, the best-for-cold-email page lists which vendors offer it. We do not claim to be best at everything.
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
- Can I try it before paying?
- Yes. The first 100 checks are free with a Google sign-in and no card, on the same mailbox check the paid plans run.
- Should I send to risky results?
- Hold them back or send slowly in a small batch. A verifier cannot confirm a catch-all mailbox, so some will bounce.
Sources
- Best email verifier for cold email, priced (SimpleVerifier)
- How to choose an email verification service: 12 questions (SimpleVerifier)
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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