Essentials of Bulk Email Address Verification

The Bulk Email Verifier specializes in authenticating a collection of email addresses. This tool conducts thorough checks on each email, including connectivity tests to the SMTP server without actually sending emails, and various other validations such as email type, format, and status. It also provides information on any public sources where the email might appear.

Understanding "Valid" Status and Bounce Rates in Bulk Email Verification

Email addresses marked as "Valid" by the verifier are generally reliable. The bounce rate for these emails is typically below 1%, indicating high deliverability.

Interpreting "Accept all" Status in Email Verification

An "Accept all" status on an email address indicates it is associated with a server that accepts any email sent to its domain, regardless of whether the specific address has been created. This uncertainty means that the Email Verifier cannot confirm the actual existence of the email, resulting in an "Accept all" status. These emails are considered less reliable than those with a "Valid" status. We suggest using the confidence score provided by the Email Verifier for a more cautious approach, like choosing only emails with scores above 80%.

Access and Pricing for Bulk Email Verification Services

The Bulk Email Verifier uses verification credits, which every paid plan includes in the same number as its search credits, from 2,500 a month. See pricing ; subscriptions can be cancelled at any time.

// bulk operations

Bulk Email Verifier

Upload a CSV of email addresses and verify them all for deliverability at once.

Start Bulk Processing View API

Email addressesUp to 20,000 rows a jobCSV, list or rows

email-verifier-list.csv2,500 rows · email addressescompleted

Bulk Email Verifier · /bulk/verifier2,500 / 2,500

01pendingPOST /v1/bulk/verifier201 · { "data": { "id": 1042 } }
02runninglaunch: trueprogress polled with GET /v1/bulk/verifier/1042/progress
03completedbulk.completedsigned webhook delivered to your webhook_url

GET /v1/bulk/verifier/1042/download?file=fullCharged at the first download · the job expires after 180 days

// 01 · input

The input of a bulk Email Verifier job

Upload a CSV of up to 4 MB in the app, or send a list, rows or a file to POST /v1/bulk/verifier. Columns are found from the header row; set a field index to choose one yourself.

POST/bulk/verifierColumns

email_field_index: Email address

POST/bulk/verifierOptions

find_phones: true adds phone numbers, at an extra cost
include_sources: true adds the web pages where each address was found

// 02 · api

One request starts the job

Create and launch it in one call, then follow its progress or receive a signed bulk.completed event. Each result row is what GET /email-verifier returns.

POST /bulk/verifier

curl -X POST "https://api.tomba.io/v1/bulk/verifier" \
  -H "X-Tomba-Key: $TOMBA_API_KEY" \
  -H "X-Tomba-Secret: $TOMBA_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"Email Verifier job","list":"richard@piedpiper.com\njohn@example.com","launch":true,"webhook_url":"https://hooks.example.com/tomba"}'

const res = await fetch("https://api.tomba.io/v1/bulk/verifier", {
  method: "POST",
  headers: {
    "X-Tomba-Key": process.env.TOMBA_API_KEY,
    "X-Tomba-Secret": process.env.TOMBA_SECRET_KEY,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "name": "Email Verifier job",
    "list": "richard@piedpiper.com\njohn@example.com",
    "launch": true,
    "webhook_url": "https://hooks.example.com/tomba"
  })
});
const { data } = await res.json(); // { id }

import os, requests

res = requests.post(
    "https://api.tomba.io/v1/bulk/verifier",
    headers={
        "X-Tomba-Key": os.environ["TOMBA_API_KEY"],
        "X-Tomba-Secret": os.environ["TOMBA_SECRET_KEY"],
    },
    json={
      "name": "Email Verifier job",
      "list": "richard@piedpiper.com\njohn@example.com",
      "launch": True,
      "webhook_url": "https://hooks.example.com/tomba"
    },
)
job_id = res.json()["data"]["id"]

POST /bulk/verifier

201 Created

{
  "data": {
    "id": 1042
  }
}

Each row, as GET /email-verifier returns it

200 OK

{
  "data": {
    "email": {
      "email": "richard@piedpiper.com",
      "result": "deliverable",
      "status": "valid",
      "score": 99,
      "smtp_provider": "Google",
      "mx": {
        "records": [
          "aspmx.l.google.com",
          "alt1.aspmx.l.google.com"
        ]
      },
      "mx_check": true,
      "smtp_server": true,
      "smtp_check": true,
      "accept_all": false,
      "greylisted": false,
      "block": false,
      "gibberish": false,
      "disposable": false,
      "webmail": false,
      "regex": true,
      "whois": {
        "registrar_name": null,
        "referral_url": null,
        "created_date": null
      }
    },
    "sources": [
      {
        "uri": "https://piedpiper.com/blog/engineering",
        "website_url": "piedpiper.com",
        "extracted_on": "2024-06-01T09:14:07+01:00",
        "last_seen_on": "2025-01-10T17:02:44+01:00",
        "still_on_page": true
      }
    ],
    "phone_data": null
  }
}

// 03 · cost and limits

What a job costs

Nothing is charged to create or launch a job. Its cost is charged once, at the first download of its results.

// billing per row

1 verification credit per row, except disposable addresses. Plus 5 search credits per row with phone data.

Bulk billing in the docs

Rows: up to 20,000 per job
Jobs created: 15 per day for each type
Running jobs: 2 per type
Downloads: 25 per day for each job
Request size: 4 MB (CSV, list or rows)

// 04 · use it anywhere

Run Email Verifier jobs from the app or your code

The same job, the same credits: upload a file in the app, call the API, or work from a spreadsheet or a no-code tool.

The full request reference: /api/bulk/email-verifier

// customers

Teams that run Email Verifier jobs

Tomba is my go-to to validate emails. Even in a waterfall process with multiple tools, Tomba is usually the top choice.
Nuno PoçoSales Automation Architect, clickworks.io
The data is always fresh, and the n8n integration is excellent. Support is very responsive. I'd rate it 9/10.
Benjie MalinaoCo-Founder & CTO, Channel Automation

// faq

Frequently Asked Questions

Still have questions? Visit the help center

const res = await fetch("https://api.tomba.io/v1/email-finder?domain=piedpiper.com&first_name=Richard&last_name=Hendricks", { headers: { "X-Tomba-Key": process.env.TOMBA_API_KEY, "X-Tomba-Secret": process.env.TOMBA_SECRET_KEY } }); const { data } = await res.json();

import os, requests res = requests.get( "https://api.tomba.io/v1/email-finder?domain=piedpiper.com&first_name=Richard&last_name=Hendricks", headers={ "X-Tomba-Key": os.environ["TOMBA_API_KEY"], "X-Tomba-Secret": os.environ["TOMBA_SECRET_KEY"], }, ) data = res.json()["data"]

{ "data": { "email": "richard@piedpiper.com", "first_name": "Richard", "last_name": "Hendricks", "full_name": "Richard Hendricks", "website_url": "piedpiper.com", "company": "Pied Piper", "pattern": "{first}", "department": "executive", "type": "personal", "position": "CEO", "country": "US", "gender": "male", "twitter": null, "linkedin": "https://www.linkedin.com/in/richard-hendricks", "score": 100, "accept_all": false, "phone_number": true, "verification": { "date": "2025-01-15T10:32:00+01:00", "status": "valid" }, "sources": [ { "uri": "https://piedpiper.com/blog/engineering", "website_url": "piedpiper.com", "extracted_on": "2024-06-01T09:14:07+01:00", "last_seen_on": "2025-01-10T17:02:44+01:00", "still_on_page": true } ], "phone_data": [] } }