verifykit
CSV & Excel · real SMTP verification

Bulk email checker
for clean lists

Upload your list, verify thousands of addresses in minutes, export the clean rows. Real SMTP — not regex.

Start bulk checkingRead docs

Four steps to a clean list

Upload, verify, filter, export — the whole workflow takes minutes.

01

Upload your list

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

02

We verify every email

Syntax, MX, disposable, SMTP — every layer runs in parallel for speed.

03

Review & filter

Browse by status: valid, risky, or invalid. Sort by quality score or grade.

04

Export clean list

Download as CSV — all rows or filtered to only valid mailboxes.

Why clean lists win

Bad lists cost you money

Every invalid address you keep is a bounce waiting to happen — and a hit to deliverability that compounds with every campaign.

Protect sender reputation

Bounce rates over 2% damage your domain. Clean before you send.

Improve deliverability

Inbox placement goes up when invalid + disposable + role-based addresses are stripped first.

Cut sending costs

Most ESPs charge per send. Removing 10–20% of dead addresses pays for itself.

Get accurate metrics

Open and click rates skew up when the denominator is real users — not bounce-prone junk.

Deduplicate automatically

Bulk runs strip exact + near-duplicates before they cost you a validation.

CSV / Excel friendly

Drop in the file you already have. Get the same file back, enriched with verdicts.

Live playground

Try a single check first

See exactly what comes back before you upload your whole list.

Open playground

Simple pricing

Bulk validation included from Growth up. Cancel anytime.

20% off · first 3 months

Starter

$7.20/ mo
$920% off
$0.0018 / validation
  • 5,000 validations / month
  • real SMTP verification
  • single API key
  • validation history
Get Starter
20% off · first 3 months

Growth

$15.20/ mo
$1920% off
$0.0013 / validation
  • 15,000 validations / month
  • bulk validation
  • real SMTP verification
  • email OTP 2FA (25k/mo)
Get Growth
20% off · first 3 months

Pro

$39.20/ mo
$4920% off
$0.001 / validation
  • 50,000 validations / month
  • unlimited API keys
  • duplicate removal
  • webhooks & callbacks
Start with Pro
20% off · first 3 months

Unlimited

$199.20/ mo
$24920% off
$0.0001 / validation
  • unlimited validations
  • all Pro features
  • dedicated support
  • fair use up to 5M/mo
Get Unlimited

Bulk email checker FAQ

How many emails can I check at once?
Up to 1,000 emails per request. Larger lists are auto-batched. For multi-million-row lists, talk to us about Unlimited.
What file formats are supported?
CSV (.csv) and Excel (.xlsx, .xls). The first sheet/column with an @ in it is auto-detected as the email column.
How accurate is bulk email verification?
97%+ for addresses where SMTP verification succeeds. The remaining ~3% are catch-all domains or providers that block verification — those are flagged as “risky” so you can decide.
Will my emails be sent during verification?
No. SMTP verification ends at RCPT TO and disconnects — no message body, no inbox impact.
Can I get an API for bulk verification?
Yes. POST a JSON array to /v1/verify/bulk. Available from the Growth plan up.

Clean your email list today

Upload, verify, export. Bounce rates drop, deliverability climbs.

Get startedTry it free