Verify Email Addresses Instantly
Verify Email Addresses Instantly: upload a CSV or connect your CRM, and Cleanlist AI checks each row against 25+ providers in sequence. Every new workspace opens on Pro for 14 days with 250 credits, 3 seats.
Cleanlist AI validating email-addresses.csv. Each address is marked Verified, Likely valid, Risky, Invalid or Unknown. Of 10,000 rows, 8,612 Verified, 604 Likely valid, 431 Risky, 287 Invalid, 66 Unknown.
10,000+ users, from founders to full sales teams
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How does Cleanlist AI verify email addresses instantly?
Cleanlist AI verifies individual email addresses through a multi-step process: DNS resolution confirms the domain exists and accepts mail, SMTP handshake simulates delivery without actually sending, pattern analysis detects catch-all configurations, and behavioral signals identify dormant mailboxes. You get a Safe or Unsafe verdict, plus a confidence score for the borderline cases.
Why this is hard to do by hand
Each unverified address you send to is a bet placed with your domain's reputation. Google Workspace and Microsoft 365 judge senders as the mail arrives. One campaign with a high bounce rate can push everything your domain sends afterwards into spam, password resets and invoices included.
A bounced email costs about $2.67 once you count what follows
$2.67true all-in cost per bounced email including downstream effects
The sending fee on a bounced email is a fraction of a cent; the cost shows up later. DMA research from 2025 found that each hard bounce wears down sender reputation and cuts inbox placement on later sends. Modeled across an average 10,000-email campaign, each bounce reduces total delivered emails by 0.3-0.5 across future sends. At the DMA's B2B benchmark of $0.54 in revenue per delivered email, one bounce costs about $2.67 in lost revenue over the next 30 days. A list with a 5% bounce rate has 500 bounces, which is about $1,335 you never see. Verifying all 10,000 addresses before the send is 5,000 credits, at 0.5 per address.
Source: DMA Response Rate Report 2025; Cleanlist AI cost-modeling analysis
What a lookup costs
Each lookup walks 25+ providers in cost order, and you're charged once for what comes back: 1 credit for a verified work email, 10 for a phone number, 11 for both. Validation is 0.5 and AI qualification is 5. A lookup that finds nothing is free, and the whole team pays from one wallet.
- Verified work emails25 leads searched23 × 123
- Phone numbersVerified before anyone calls18 × 10180
- Qualification agentFit score with reasons25 × 5125
- 25+Providers queried in cost order on a single lookup
- 98%Verified work emails on our 500-lead benchmark
- 85%Phone numbers found on that same benchmark
- 0Credits for a lookup that finds nothing
How it works.
- 01
Enter the addresses
Type one email, paste a batch of up to 500, or call the API with a single address to check it inside your app or signup form.
- 02
DNS and MX lookup
Cleanlist AI checks the domain's MX records, SPF setup and DMARC policy. A domain with no mail server gets flagged right away, and obvious invalids cost no credit.
- 03
SMTP check
Cleanlist AI connects to the mail server and runs the delivery handshake (HELO, MAIL FROM, RCPT TO), then hangs up before any email is sent. The server's reply tells you whether that mailbox exists.
- 04
A second pass for hard cases
Addresses on catch-all, greylisting or rate-limited servers get a second pass: pattern analysis, past delivery data from our providers, and signals that point to an abandoned inbox.
- 05
The verdict
Each address comes back Deliverable, Undeliverable, Risky (catch-all or greylisted) or Unknown (the server timed out). Risky addresses carry a sub-score, so you set your own cut-off.
What you get.
98% verified work emails
That's on our 500-lead benchmark. Cleanlist AI checks each email and flags catch-all and disposable addresses before you send.
25+ data providers
Cleanlist AI asks them one at a time and stops at the first deliverable result. When one provider has nothing, the next one gets its turn.
No code required
Upload a CSV or connect your CRM. If your engineers want it, the API is there from the Pro plan.
14-day Pro trial
250 credits and 3 seats on Pro for 14 days. You don't need a card or a sales call to start.
Manual process vs Cleanlist AI.
| Feature | Manual | Cleanlist AI |
|---|---|---|
| Checking a single email | Send a test email and wait hours for a bounce | One API call, and no email is sent |
| Greylisting handling | Can't tell, so it looks valid | Retried after a delay to get past the greylist |
| Catch-all domains | Reported 'valid' every time | Risk-scored from past delivery patterns |
| API integration | Manual, one address at a time | REST API on Pro and up, with batch jobs you poll |
| Cost per verification | $0 up front, paid later in bounces and reputation | 0.5 credits per address |
| Mailbox activity detection | No visibility | Dormant inboxes flagged from activity signals |
How accurate is Cleanlist AI's data?
Cleanlist AI returned 98% verified work emails and 85% phone numbers on our 500-lead benchmark, pulling from 25+ data providers. Each lookup stops at the first deliverable result, meaning a verified or likely-valid email.
What do I get when I sign up?
A 14-day Pro trial: 250 credits, 3 seats, and every Pro feature. After it, the Free plan gives you 50 credits a month. A verified work email costs 1 credit, a phone number 10, and a miss nothing.
What data providers does Cleanlist AI use?
Cleanlist AI runs a waterfall across 25+ B2B data providers. For each record it asks one, moves to the next when that one has no match, and stops at the first deliverable result.
Can I connect my CRM?
Yes. HubSpot and Salesforce sync both ways on the Pro and Enterprise plans, and Salesloft and Lemlist take a one-way push. You can also upload a CSV, or use the REST API from Pro.
How long does it take to verify my data?
It depends on the size of the file and how far down the waterfall each row has to go. Cleanlist AI runs the whole CSV as one job, so you upload once and download or sync the results when it's done.
Does email verification actually send an email to the address?
No. Cleanlist AI starts the SMTP delivery handshake with the mail server and disconnects before any message is sent. The recipient gets nothing, and nothing shows up in their inbox.
Can I verify a single email address in real-time on a signup form?
Yes, through the API on Pro and up. Call it when the form is submitted to block disposable and invalid addresses at signup, which keeps fake accounts and bad addresses off your list from the first day.
Why do some verification tools give different results for the same address?
Because one SMTP check can return different answers depending on server load, greylisting and rate limits, and a single-provider tool only sees the one it got. Cleanlist AI runs the address through more than one provider and compares the results, which removes most of that noise.
Describe the job once. An agent runs it every week.
Clu turns one sentence into an agent. It searches 1B+ profiles, finds verified emails and phone numbers across 25+ providers, adds the people to your sequence and posts each run to Slack.
Weekly ICP outbound
Built by Clu from: “Every week, find 500 new people who match my ICP, get their emails and phones, and add them to Series B outbound.”
- Searched 1B+ profiles for new ICP matches500 foundPeople Search
- Ran the waterfall across 25+ providers487 emails · 412 phonesWaterfall
- Verified every email and phoneSMTP + catch-allVerification
- Added them to Series B outbound500 peopleSequences
- Posted the run to #pipelineSlackAgents
Friday 4:52 PM15 replies · 5 calls booked
Everything in the 14-day Pro trial
- Clu and agentsDescribe the job in one sentence. Clu builds the agent, runs it on a schedule or a CRM trigger and posts every run to Slack.
- People and Company SearchFind your buyers in 1B+ profiles from one sentence. Searching costs 0 credits.
- Waterfall enrichmentAsk 25+ providers in order and stop at the first verified email or phone number. 98% verified work emails and 85% phone numbers on a 500-lead benchmark.
- Email verificationRun SMTP and catch-all checks on every address before it reaches a sequence, at half a credit an email.
- ICP scoringScore every lead 0 to 100 against your ICP, with the reasons written down. The Research and Qualification skills do the digging.
- SequencesSend email from your reps' own inboxes, with call tasks. A reply stops the sequence. Sending costs 0 credits.
- CRM syncTwo-way sync with HubSpot, Salesforce and Pipedrive. Push finished lists to Outreach, Salesloft and Lemlist.
- Chrome extensionGet a verified email and phone number in one click on LinkedIn, Sales Navigator, Salesforce and HubSpot.
- MCP and APIRun the same search and waterfall from Claude or ChatGPT with 36 MCP tools, or from your own code with the REST API.
14 days of Pro, free: 250 credits, 3 seats, agents, Sequences and Clu in Slack. Then Free at 50 credits a month, or Starter at $49 and Pro at $89 a seat a month.
Hand the job to an agent.
Upload a CSV or connect HubSpot, Salesforce or Pipedrive, and run it on your own data today.
14 days of Pro, free.
Get 14 days of Pro, free.
250 credits and 3 seats. Sign up with your work email for 100 more.