How to Find a CTO's Email Address (2026)

You find a CTO's email by looking it up in a data source first and guessing from a name pattern only when the lookup is empty. A lookup returns an address someone has already tested. A guess is a coin flip you must verify.

CTO addresses come from four places. A data provider holds a work address it collected and checked. A company site, docs page or engineering blog lists a shared inbox, which is rarely the CTO's own. A name pattern gives you a guess. A commit history or open source profile sometimes exposes a personal address, which is a poor fit for business outreach.

Only the first is worth building a process around. The other three are fallbacks, and this guide follows that order.

CTOs are harder than most titles. At a 20-person startup the CTO is a co-founder with an alias and a filtered inbox. At a large company the title may sit three levels below the real technology decision maker. Size the audience first so you know which case you are in.

This guide uses the LeadOcean API. Every step has a request you can run.

TL;DR

• It takes about 15 minutes to size the audience, find one CTO's address and read its status.
• The walkthrough spends about 4 records: up to 3 from the search and 1 from the reveal. Counts are free.
• Send only to verified, catch_all_valid or catch_all. Anything you guessed gets verified first.

Prerequisites

• A LeadOcean API key from app.leadocean.io. The free plan has 1,000 records, one-off, and no card.
• The key in your shell as $LEADOCEAN_API_KEY.
• curl and jq.
• A target company domain. The examples use acme.com.

export LEADOCEAN_API_KEY="paste-your-key-here"

Step 1: Size the CTO audience for free

Count how many CTOs you can mail before you spend a record. Send count=true and limit=1 as query parameters. Arrays go comma-separated.

curl -s -G https://api.leadocean.io/v1/people/search \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  --data-urlencode "title=CTO,Chief Technology Officer" \
  --data-urlencode "jobLevel=C-Team" \
  --data-urlencode "salesRegion=EMEA" \
  --data-urlencode "emailStatus=verified,catch_all_valid,catch_all" \
  --data-urlencode "count=true" \
  --data-urlencode "limit=1" | jq '.meta | {total, totalIsExact, countOnly}'

salesRegion takes NORAM, LATAM, EMEA or APAC. Swap in country=DE for one market. REST meta.total stops at 100,000, so a big region comes back as a floor with totalIsExact false.

Add employeeRange=11-50 to find startup CTOs, or employeeRange=1001-5000 for mid-size engineering orgs. Each range changes the count, so run it before you decide where to spend records.

Step 2: Find the CTO at your target company

Search by company domain and title. The search returns a thin row with no address in it. The row carries a person_id and flags that say whether we hold an email.

curl -s https://api.leadocean.io/v1/people/search \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "domain": ["acme.com"],
    "title": ["CTO", "Chief Technology Officer"],
    "jobLevel": ["C-Team"],
    "limit": 3
  }' | jq '.data[] | {person_id: .meta.source_ids.person_id, contact_data}'

Each person returned costs 1 record. Keep limit small. Title values are keywords, so a few rows may be a deputy or an "Associate CTO". Check the title before you pick one.

Small companies often list the technical lead as founder, not CTO. For those, swap the title filter for "seniority": ["founder", "owner"] plus "jobFunction": ["Engineering"]. Sizing with count=true first shows which version returns people.

Step 3: Reveal the address

Send the person_id to enrich with reveal_email set to true. Enrich takes exactly one of linkedin_url, email, phone or person_id. There is no name plus domain lookup, which is why Step 2 comes first.

curl -s https://api.leadocean.io/v1/people/enrich \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"person_id": "PERSON_ID_FROM_STEP_2", "reveal_email": true}' \
  | jq '.data.contact_data | {email_status, contact_emails}'

This costs 1 record. A person we hold nothing for is a 404 and costs nothing. If you only want a deliverable work address, GET /v2/people/email/work with the same person_id returns one current-employer address or null. It costs 1 record per call, even when it finds nothing.

Step 4: Read the status before you send

The status says how far to trust the address. verified was tested. catch_all_valid means we confirmed the mailbox on a domain that accepts everything. catch_all means the domain accepts everything and the mailbox is unproven.

curl -s https://api.leadocean.io/v1/people/enrich \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"person_id": "PERSON_ID_FROM_STEP_2", "reveal_email": true}' \
  | jq -r '.data.contact_data
    | select(.email_status | IN("verified","catch_all_valid","catch_all"))
    | .contact_emails[0].email'

Empty output means the status failed the filter. LeadOcean gives no refund for bounced emails, so this check is your only protection. Treat catch_all as sendable at low volume, not as proof. Our catch-all explainer covers why.

Step 5: Fall back to a name pattern

When the data holds no address, build candidates from the CTO's name and the company domain. Most companies use one of four shapes. Pick the one you can confirm from a known address at the same company.

first="jane"; last="doe"; domain="acme.com"
printf '%s\n' "$first@$domain" "$first.$last@$domain" "${first:0:1}$last@$domain" "${first:0:1}.$last@$domain"

Engineering teams are the worst case for guessing. Technical founders often use a short first-name address, a plus alias or a custom domain. A pattern that works for staff may miss them.

Never send to a candidate you have not verified. Run each one through an email verifier you trust first. A domain that accepts all mail cannot confirm any single mailbox, so a guess there stays a guess.

Step 6: Verify and send in small batches

Verify before the first send, then start small. A bad batch to a technical audience gets flagged fast, and a CTO who marks you as spam is gone for good.

Send 20 to 50 messages first and watch the bounce count. If more than a few bounce, stop and re-check the status filter in Step 4. Keep the message short and specific to their stack or team size, not a generic template.

What you get

Step 1 is free. We ran it on 2026-10-21 for each sales region with leadocean_count_leads. The counts are mailable CTOs (verified, catch_all_valid or catch_all, the tool default), not every CTO we hold. The title filter is CTO or Chief Technology Officer with job level C-Team.

Worldwide the same filter counted 171,357, spread across about 115,000 employers. The four regions add up to less, because some records carry a country but no sales region. For one country, country=US counted 67,671 on the same day.

The REST call in Step 1 would show the worldwide figure as a 100,000 floor, because REST meta.total stops there. The MCP tool reported exact totals on the run date.

A revealed person comes back in the shape below. This is the response shape from the API reference, with placeholder values.

{
  "success": true,
  "data": {
    "profile_data": { "...": "name, title, company" },
    "contact_data": {
      "has_email": true,
      "email_status": "verified",
      "email_type": "work",
      "contact_emails": [
        { "email": "jane.doe@acme.com", "type": "work", "status": "verified" }
      ]
    }
  }
}

Troubleshooting

FAQ