SimpleVerifier Team · Reviewed
How do I clean an email list before sending?
Remove duplicates and malformed addresses, drop anyone who has bounced or unsubscribed, then run the rest through a verifier that does a real SMTP mailbox check. Send to the valid addresses, hold back or test the risky ones in a small batch, and never mail the invalid ones. Clean the list immediately before each campaign.
The order that works
Do the free steps first so you do not pay to verify rows you were going to delete anyway.
- Normalise: trim spaces, lower-case, and remove exact duplicates (and Gmail dot and plus variants if you want one row per person).
- Remove suppressions: previous hard bounces, unsubscribes and spam complaints never go back on a list.
- Verify: upload the CSV to a verifier that connects to the recipient's mail server and asks whether the mailbox exists. Syntax-only checkers cannot do this.
- Segment by result: valid goes in the campaign, invalid is suppressed, risky is handled separately (see the risky answer).
- Send in a small first batch and watch the bounce rate before sending the rest.
What cleaning cannot do
A verifier tells you whether an address is likely to accept mail. It cannot tell you whether the person wants it, whether you have consent, or whether your message will land in the inbox rather than spam. A clean list with a poor sending reputation still goes to spam; see what verification does and does not fix.
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
- Is it safe to upload my list to a verifier?
- Check the vendor's privacy terms first. SimpleVerifier's privacy policy rules out using customer lists for our research, and the [security page](/security) describes how data is handled.
- Should I clean the list before or after importing it into my sending tool?
- Before. Importing first means bad addresses can be sent to by an automation before you get to them.
Sources
- Google email sender guidelines
- Bounce limits by platform, read from each vendor's own docs (SimpleVerifier, 1 Oct 2026)
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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