How to Find Business Email Addresses (With Three API Requests)

The reliable way to find a business email is to query a database that stores the address with a deliverability status. Guessing a pattern and hoping is the fallback, not the method.

Most guides on this topic list browser extensions and tell you to try first.last@company.com. This one is for people who want a repeatable request. You will size a list, find the people, and reveal one address each, with a status you can filter on.

Pick this route when you have a market ("US C-level leaders at 11-50 person companies") or a company domain, not a single name.

TL;DR

• The first run takes about 15 minutes with curl.
• It spends about 2 records per contact: 1 for the search row, 1 for the reveal. Counts, sizing and a 404 are free.
• Send only to verified, catch_all_valid or catch_all. Check email_status before every send.

Prerequisites

• A LeadOcean API key from app.leadocean.io. Free is 1,000 records, one-off, no card.
• The key exported as $LEADOCEAN_API_KEY.
• curl and jq. Examples use acme.com and Jane Doe as placeholders.

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

Step 1: Size the audience for free

Count before you spend. 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 "jobLevel=C-Team" \
  --data-urlencode "country=US" \
  --data-urlencode "employeeRange=11-50" \
  --data-urlencode "count=true" \
  --data-urlencode "limit=1" | jq '.meta | {total, totalIsExact, countOnly}'

REST meta.total stops at 100,000. A bigger market returns a floor with totalIsExact false. The MCP tool leadocean_count_leads is also free.

Step 2: Search the people

Search returns a thin row per person, not an address. Send a flat JSON body. Filters are arrays of strings, limit runs 1 to 100, and you page with cursor.

curl -s https://api.leadocean.io/v1/people/search \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobLevel": ["C-Team"],
    "country": ["US"],
    "employeeRange": ["11-50"],
    "emailStatus": ["verified", "catch_all_valid"],
    "limit": 25
  }' | jq '.data[0], .meta.nextCursor'

Each person returned costs 1 record. Pass meta.nextCursor back as cursor for the next page. One search pages to 10,000 rows, then meta.depthCapped is true. Narrow the filters instead of walking further.

Start from a company instead? Use GET /v1/companies/{domain}/people, for example /v1/companies/acme.com/people.

Step 3: Reveal the address with enrich

Enrich takes exactly one of linkedin_url, email, phone or person_id. There is no name plus domain lookup, so take the person_id from the search row at meta.source_ids.person_id.

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}' \
  | tee person.json | jq '.data.contact_data | {email_status, email_type, contact_emails}'

It costs 1 record. Someone we hold nothing for is a 404 and costs nothing. Revealing adds every email and phone we hold at no extra charge.

Step 4: Read the status before you send

The address is only half the answer. email_status tells you whether to send. A verified address is safe to mail. A catch_all domain accepts everything, so the risk is higher. Filter the file you saved in Step 3; a second enrich call would spend another record.

jq -r '.data.contact_data
      | select(.email_status | IN("verified","catch_all_valid","catch_all"))
      | .contact_emails[0].email' person.json

Skip risky, invalid, role, disposable and spam_trap. We do not refund bounced emails, so the filter is your protection.

Step 5: Do it from an AI agent

The hosted MCP server at https://api.leadocean.io/mcp signs in with OAuth, so you paste no key. It has 13 tools. Counting is free, so ask for the count first.

Count US C-Team people at companies with 11-50 employees using
leadocean_count_leads. Report the total and distinctCompanies, and say
which email filter the count used. Do not run a search yet.

Step 6: Export a whole list

For hundreds of rows, export instead of paging. POST /v1/exports takes the same filters as people search, up to 50,000 rows a request and 500,000 a day. Bulk CSV export is not on Free.

curl -s https://api.leadocean.io/v1/exports \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "US C-Team 11-50",
    "filters": {"jobLevel": ["C-Team"], "country": ["US"],
                "employeeRange": ["11-50"],
                "emailStatus": ["verified", "catch_all_valid"]},
    "limit": 5000,
    "preset": "full"
  }'

Poll GET /v1/exports/{id}, then GET /v1/exports/{id}/download. Every row costs 1 record. The Exports page in the app does the same with a filter builder and shows the price first.

What you get

Step 1 is free. We ran leadocean_count_leads on 2026-10-21 with job level C-Team, country US and headcount 11-50, on the default mailable filter (verified, catch_all_valid or catch_all).

The mailable people span about 339,596 employers (an estimate, not exact). Roughly a quarter of the people who match have an address worth sending to. Narrow by industry or title before you export.

A revealed person comes back in this shape. 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