CSV & Excel support · real SMTP verification

bulk email checker
for clean lists

Upload your email list and verify thousands of addresses in minutes. Our bulk email checker uses real SMTP verification to tell you exactly which emails are valid, risky, or dead.

bulk-check · contacts.csv
5,247 emails processed
5,247
total
4,182
valid (79.7%)
641
risky (12.2%)
424
invalid (8.1%)
emailstatusscoregrade
[email protected]
valid
0.97excellent
[email protected]
risky
0.55fair
[email protected]
invalid
0.00poor
... and 5,244 more rows

How bulk email checking works

Four steps from upload to clean list. Most lists finish processing in under 5 minutes.

1

Upload your list

Drag and drop a CSV or Excel file with your email addresses. We auto-detect the email column.

2

We verify every email

Each email goes through syntax, MX, disposable, and SMTP checks. Processed in parallel for speed.

3

Review & filter results

Browse results by status: valid, risky, or invalid. See deliverability scores and quality grades for each email.

4

Export clean list

Download your verified email list as CSV. Export all results or filter to only valid addresses.

Why use a bulk email checker?

Sending to unchecked lists wastes money and damages your domain. Here's what bulk email checking does for you.

Protect sender reputation

High bounce rates damage your domain reputation. Bulk checking removes invalid addresses before you send, keeping bounce rates under 2%.

Improve deliverability

Clean email lists mean more emails land in the inbox. Remove disposable, role-based, and non-existent addresses that hurt your campaigns.

Save money on sends

Stop paying to send emails that bounce. Every ESP charges per email. Removing 10-20% of invalid addresses directly cuts your sending costs.

Get accurate metrics

Invalid emails skew your open rates and click rates. Clean lists give you real engagement data to make better marketing decisions.

Supported file formats

Upload your email list in any of these formats. We auto-detect the email column.

📄

.CSV

Comma-separated values. The most common format for email exports from CRMs and ESPs.

📊

.XLS

Classic Excel format. Works with exports from older spreadsheet applications and legacy systems.

📗

.XLSX

Modern Excel format. The default for Excel, Google Sheets exports, and most modern tools.

Live API Playground

Test the API with real validation. Every request hits our live infrastructure.

~/dev/email-validator
email:
Generated cURL command
curl -X POST https://api.verifykit.io/v1/verify \
-H "Authorization: Bearer vk_live_..." \
-d '{"email":"[email protected]"}'
HTTP 200 OK

Enter an email and validate to see results

$ ./validate --email [email protected]

~200ms
Average response time
99.9%
API uptime
1000+
Free validations/month

Bulk email checker pricing

Bulk checking is available on the Growth plan and above. Start with single checks for free.

Free

$0/month
  • • 1,000 single checks/month
  • • basic email validation
  • • API access
  • • no bulk checking
Start free

Starter

$9/month
  • • 5,000 checks/month
  • • real SMTP verification
  • • validation history
  • • no bulk checking
Get starter
Bulk enabled

Growth

$19/month
  • • 15,000 checks/month
  • • real SMTP verification
  • • validation history
  • • bulk email checking
Get growth

Pro

$49/month
  • • 50,000 checks/month
  • • bulk email checking
  • • duplicate removal
  • • webhooks & callbacks
Get pro

Unlimited

$249/month
  • • unlimited bulk checks
  • • all pro features
  • • dedicated support
  • • fair usage up to 5M/month
Get started

Bulk email checker FAQ

How many emails can I check in bulk at once?

Each bulk upload supports up to 1,000 emails per file. You can upload multiple files. Your monthly quota depends on your plan: Growth (15,000/mo), Pro (50,000/mo), or Unlimited (up to 5M/mo).

How long does bulk email checking take?

Most lists are processed within minutes. A 1,000 email list typically completes in 2-3 minutes with full SMTP verification. Emails are processed in parallel batches for speed.

What file formats does the bulk checker accept?

We accept CSV (.csv), Excel (.xls), and modern Excel (.xlsx) files. The bulk checker auto-detects the email column in your file, so no special formatting is needed.

Can I export the bulk check results?

Yes. After processing, you can export results as a CSV file. Filter by status (valid, risky, invalid) before exporting, or download the complete results with all verification details.

Which plan do I need for bulk email checking?

Bulk email checking requires the Growth plan ($19/month) or higher. Free and Starter plans support single email verification via the API and playground. All paid plans include real SMTP verification.

Does the bulk checker remove duplicates?

Automatic duplicate removal is available on the Pro plan ($49/month) and above. On the Growth plan, duplicates are checked but counted toward your monthly quota. You can manually deduplicate before uploading.

Clean your email list today

Start with the Growth plan at $19/month for bulk email checking with SMTP verification.