SimpleVerifier Team · Reviewed
How do I verify a CSV export from HubSpot, Apollo or Mailchimp?
Export the contacts as a CSV, upload the file at /verify, and download the valid, risky and invalid results with your other columns kept. Import only the valid rows back and suppress the invalid ones. The first 100 checks are free with a Google sign-in, and Pro is $39 a month.
The export, tool by tool
Each tool has its own export path, linked to its own help article on the matching verify-export page.
| Tool | Where the export lives | What to watch |
|---|---|---|
| HubSpot | CRM > Contacts > Export, format CSV; the file arrives by email. | Files over 2 MB come zipped, and unsubscribed contacts are included unless you filter them out first. |
| Apollo | Select the contacts, click Export, then download from Settings > Import & Exports > CSV Exports. | Treat the source's own verified flag as unconfirmed and check before sending. |
| Mailchimp | Audience > Export audience > Export CSV; download from the email Mailchimp sends. | The download can be a ZIP with separate subscribed, unsubscribed and cleaned files. Verify the subscribed file only. |
Verify and put the results back
The same four steps for all three.
- Drop the CSV on /verify. Your other columns, including the HubSpot Record ID, are passed through, so the results match back to your records.
- Download the valid, risky and invalid files. Risky means a catch-all or a server that will not confirm the mailbox; it is never guessed valid.
- Re-import with an update-existing option and map the status to a contact property, or import only the valid file.
- Suppress invalid addresses, and send the risky ones in a small test batch of 100 to 300 before the rest.
Size and cost of the file
CSV uploads take up to 100,000 rows per file, so split a bigger export first with the email list splitter. List jobs run at about 30 rows a minute averaged over a day, so allow time for a very large file. Pro is $39 a month with no per-email credits: the first 100,000 a month run at full speed, then slower, never cut off. For a list you only check once, see what each list size costs.
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
- Unlimited email verification on Pro means the first 100,000 checks a month at full speed, then slower, never cut off. It is not instant: checks are paced and capacity is shared by all customers, so small lists finish sooner, a very large list queues and can take days rather than hours, and every job shows its estimated finish time. Bad syntax, dead domains and disposable addresses return at once.
- 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 7 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 verify a HubSpot, Apollo or Mailchimp export without connecting my account?
- Yes. Upload the CSV on the verify page. No account connection is needed for a file.
- Do my other columns survive?
- Yes. Names, company fields and IDs are passed through, so you can match results back to your records.
- How many rows can one file hold?
- Up to 100,000 rows per CSV. Split larger exports first.
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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