Send with certainty.

Verify every address before it costs you deliverability.

Fewer bounces on every send
Stronger email marketing ROI
Sign-up forms protected from junk
A sender reputation that stays intact

Start verifying

100 free credits. No card required.

paste addresses or upload a CSV…

Verify

sarah.chen@northwind.com checkingDeliverable98

jamie@gmial.com checkingUndeliverable3

Did you mean jamie@gmail.com?

hello@papertrail.co checkingRisky61

x9f2k@tempmail.cc checkingRisky12

Syntax · DNS · disposable · role · typo checks are instant.SMTP verdict ~2s

Works with major email marketing tools.

MCP · Agents and automation

Verify from inside

Connect Qualisend once and your assistant can verify an address or clean a list in plain language — a real mailbox check behind every verdict. No code, no CSV round-trip, no pasting keys between tools.

See how it works

Real-time verification

Answers in seconds.

One address, one verdict, while the form is still open.

Wire it into your signup flow and bad addresses never enter your list.

More about single checks

Newsletter sign-uplive

sarah.chen@northwind.com

Syntax checkingwell-formed

DNS · MX checkingMX found

Disposable checkingclean

Role address checkingpersonal

Typo checkingnone

SMTP mailbox probingexists

resolving verdict…

Deliverable98

Instant checks · SMTP verdict in ~2s.

Bulk cleaning

Clean lists, fast.

Upload a CSV, watch it resolve live, download the addresses worth keeping.

Every row gets the full pipeline. Progress streams to your dashboard in real time, duplicates are only charged once, and the cleaned export slots straight back into your sending tool.

More about bulk cleaning

q3-subscribers.csv

12,402 rows

verifying…

d.laurent@maisonbleue.frqueuedDeliverable

orders@velvetgoods.shopqueuedDeliverable

k.osei@harborpine.comqueuedDeliverable

jenny_84@tempmail.ccqueuedRisky

amy.wong@gmial.comqueuedUndeliverable

hello@papertrail.coqueuedRisky

Deliverable11,690Risky468Undeliverable210Unknown34

Trusted by experts. Loved by customers.

Honest verdicts

Catch-all, handled honestly.

Some domains accept every address. We tell you - instead of guessing.

No verifier can confirm a mailbox behind a catch-all domain; anyone claiming otherwise is guessing. Qualisend detects catch-all per domain, labels it clearly, and scores it so you can decide your own risk tolerance.

More about statuses

Deliverable

The mailbox exists and accepts mail - safe to send.

Risky

May bounce or land in spam - the address can't be fully confirmed as safe.

Undeliverable

The address doesn't exist or was refused - it will bounce.

Unknown

The mail server gave no clear answer - worth trying again later.

List protection

Filter the junk.

Disposable inboxes, role addresses and obvious typos - flagged before they hurt.

Throwaway domains burn your engagement metrics, role addresses rarely convert, and typos bounce hard. Each is flagged separately with its own sub-flag so you can keep, cut, or fix them deliberately.

More about filtering

Campaign bounce rate

Illustrative: same list, before and after cleaning

Before cleaning4.7%

After cleaning0.4%

Mailbox providers throttle senders whose campaigns bounce. Removing undeliverable addresses before you send keeps your domain under their thresholds.

Developers

An API you'll like.

REST, API keys with scopes, per-key rate limits, JSON that makes sense.

Verify at signup, batch overnight, or wire Qualisend into your own product. The same pipeline that powers the dashboard is one POST away.

More about the API

Verifications

Last 12 weeks

64,231

deliverable 88%risky 6%undeliverable 4%unknown 2%

Try it

Check one, free.

No account needed. Five checks per hour, on the house.

The free check catches typos, fake domains, and throwaway addresses. To confirm the inbox really exists and won't bounce, run the full check.

API

Built for builders.

One POST, one verdict - in whatever language you already write.

# Verify a single address
curl -X POST https://app.qualisend.com/api/v1/verify \
  -H "Authorization: Bearer qs_live_..." \
  -H "Content-Type: application/json" \
  -d '{"email":"jane@example.com"}'

200 OK · application/json

{
  "email": "jane@example.com",
  "status": "deliverable",
  "reason": "accepted_email",
  "score": 98,
  "sub_flags": { "free_mail": false, "role": false },
  "did_you_mean": null
}