Find CTO Email Addresses
Search by job title, company or industry, and Cleanlist AI looks up the work email and phone number of each person. On our 500-lead benchmark it returned 98% verified work emails and 85% phone numbers.
Cleanlist AI People Search. The sentence "CTOs, ex staff or principal engineers, joined since Jan 2025, with Kubernetes skills, at Series A-B software companies with 51-200 staff funded since April, in the US or Canada. No open Salesforce opps." becomes 10 filters (Job title: CTO, Past titles: Staff Engineer, Principal Engineer, Joined current job after: Jan 2025, Skills: Kubernetes, Industry: Software Development, Company headcount: 51-200, Funding stage: Series A, Series B, Most recent funding after: Apr 2026, Country / region: United States, Canada, Exclude: Active opportunities), previews about 130 people and adds them to the list New CTOs, Series A-B.
10,000+ users, from founders to full sales teams
- Switched from
ZoomInfo - Case study
HackerOneSwitched from
Apollo- Switched from
Clay - Case study
Sumo LogicSwitched fromClay- Switched fromApollo
- Case study
- Switched fromZoomInfo
- Switched fromZoomInfo
G2
Chrome Web Store
AppSumo
How does Cleanlist AI find CTO email addresses?
Cleanlist AI's waterfall enrichment is specifically effective for CTO lookups because it combines enterprise-grade B2B databases with startup-focused data sources. Apollo or ZoomInfo may cover the CTO of a Fortune 500 company. The waterfall asks 25+ providers in sequence, so a seed-stage CTO that one provider misses can still turn up at the next. Every email gets a live SMTP check, and personal-domain addresses are flagged so you can tell a work inbox from a personal one.
Why this is hard to do by hand
41% of CTOs at companies under 200 employees run business email through a custom domain setup, a Google Workspace alias or a personal address (LinkedIn Talent Insights, 2025). Most CTOs work at startups and early-stage companies, where email setups rarely follow a pattern, and technical founders use email masking services more than most buyers. If you sell security, DevTools or infrastructure, the CTO is often the decision-maker, and the big data providers are thinnest in the startup and mid-market segments where most CTOs work.
Why startup CTOs are harder to find than enterprise CTOs
Enterprise CTOs at companies over 1,000 employees usually follow the firstname.lastname@company.com pattern, and the big B2B databases cover them well. Startup CTOs vary more: firstinitial@company.com, shared aliases like tech@, and personal Gmail addresses used as the main work inbox. Startup domains also change more often, after a rebrand or a pivot, so an address that worked last year can bounce today. One provider rarely has all of them. Cleanlist AI asks 25+ providers in sequence and runs a live SMTP check on what comes back, so a startup CTO missing from one source can still turn up in the next.
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
Search by company or industry
Enter a company name or domain, or filter by industry, headcount and funding stage to find CTOs at the companies you sell to.
- 02
Filter by CTO and engineering titles
Cleanlist AI matches CTO, Chief Technology Officer, VP Engineering, Co-founder & CTO and Technical Co-founder in one search.
- 03
Check the email and its domain
Each result says whether the email sits on the company domain, a personal domain or a separate Google Workspace domain, along with its verification status.
- 04
Add technical context
Add a Smart Agent column and ask for what you need, like engineering team size or recent job postings. It researches each company and writes the answer into the row.
- 05
Export with your segments
Download a CSV or push the list to HubSpot or Salesforce with the columns you built, then run the sequence in the tool you already use.
What you get.
Verified work emails
Cleanlist AI checks each email for deliverability before it comes back, so your rep doesn't waste a send on a dead inbox.
Search by company or industry
Filter by company name, domain, industry, location or employee count.
Phone numbers too
Mobile and office numbers that ring the person's own phone, at 10 credits per number found.
Work contacts only
Cleanlist AI returns work contact data for B2B sales research. It isn't a people finder for private individuals.
14-day Pro trial
Run your first list on Pro: 14 days, 250 credits, 3 seats.
Manual process vs Cleanlist AI.
| Feature | Manual | Cleanlist AI |
|---|---|---|
| Startup CTO coverage | Limited (major providers miss early-stage) | 25+ providers in sequence, startup sources included |
| Custom domain detection | Not available | Flags personal vs corporate domains |
| What the company builds on | A second tool (BuiltWith, Wappalyzer) | A Research skill column researches it per company |
| Time per lookup | 10-20 min (GitHub, LinkedIn, company site) | One search, 25+ providers behind it |
| Title variant matching | Must search each variant separately | CTO title variants matched in one search |
| Checked before you send | No, you learn from the bounce | Yes, a live SMTP check on every email |
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.
Is this data GDPR compliant?
Cleanlist AI returns work contact data for B2B sales research and isn't a people finder for private individuals. Whether your outreach meets GDPR depends on how you use the data, so check your program with counsel.
How do I find a CTO's email at a startup that is not in major databases?
Run it through a waterfall. Cleanlist AI asks 25+ providers in sequence and stops at the first deliverable email, so a seed-stage CTO that one provider misses gets another chance at the next. If none of them finds one, the lookup costs nothing.
Do CTO emails change more frequently than other executive contacts?
Yes, for two reasons. Startup CTOs change companies often, and a pivot, rebrand or acquisition can change the email domain even when the CTO stays put. Cleanlist AI stamps each record with its last-verified date, and re-running the list checks every row live against 25+ providers.
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.