Email checker
100% mailbox-level checks · 68,400 throwaway domains tracked
A throwaway address is not a good address.
We ran six live temp-mail generators through the market leader. All six came back valid. B4Valid names them: Disposable — a verdict of its own, never folded into Valid. 100 addresses go from upload to results in about one second.
Try our free email validator
(100 emails minimum)
Disposable
Accepts mail — and self-destructs. Never folded into Valid.
141ms
1 credit
✓Syntax & MX1 record
✓SMTP mailbox250 OK
✕Throwaway registrylisted · temp-mail
✕Domain agerotating MX, 11 d
!Subdomain wildcardaccepts all
Instant check & verdict
Five verdicts. Only one clears the send.
Pass/fail hides the two categories that cost money: throwaways that accept, and catch-alls that accept everything.
✓
Deliverable
Mailbox confirmed, domain has history, not on any throwaway list.
Send
✕
Undeliverable
Rejected at the server. Hard bounce if you send it.
Remove
!
Risky
Catch-all, role account, or full mailbox — accepted, unproven.
Segment
⊘
Disposable
Temp-mail generator or rotating throwaway domain. Accepts, then vanishes.
Suppress
?
Unknown
Server timed out or greylisted us. Re-checked free for 30 days.
Retry free
The finding
Disposable email detection
live
Flags addresses from 8,000+ known disposable and temporary email providers: Mailinator, GuerrillaMail, 10MinuteMail, YOPmail, Temp-Mail, ThrowAwayMail, and thousands more. Keeps your list clean of burner accounts.
8,000+ providersNamed, not guessed
Each address was created minutes before the test and could receive mail at check time. Both engines were correct about the mailbox; only one was useful about the sender.
Benchmark
Upload a hundred. Read the results.
No job queue, no email-me-when-done for lists this size. Rows stream back as they resolve; the summary counts up in front of you.
0.00s
Elapsed
0
Of 100 resolved
3
Dupes, uncharged
august-webinar.csv
103 rows · 3 duplicates removed before charging
0
Deliverable
0
Undeliverable
0
Risky
0
Disposable
0
Unknown
Get 15 free email verifications — no card needed
Start verifyingWhy check emails before you send?
46%
Deliverable
46%Deliverable475
22%Undeliverable246
16%Disposable178
10%Risky112
6%Unknown75
Verify your email list
No delays — real-time verification checks your entire list with unmatched speed and precision. See results as they happen.
Get your emails delivered
Improve the success of your campaigns by verifying addresses and ensuring your messages reach real, engaged users — not spam folders or dead inboxes.
Key type
Live key
Production. Requests draw on your credit balance.
Test key
Random verdicts, no credits consumed.
CancelCreate
Developer-friendly by design
Integrate fast with clean documentation and a simple setup — single and batch endpoints, webhooks, and a test key that never touches your balance.
Inbox
1 unread
B4B4Valid
NGNorthgate Growth
BLBrightloom
VWVestaworks
Protect sender reputation
High bounce rates and spam traps damage your sender score. Verified emails help keep your domain trusted by inbox providers.
NameArthur Morgan
Emaila.morgan@gaiml.com✕
Password•••••
Submit
Real-time validation
Verify addresses as users type to block fake or invalid entries, ensuring clean data and reliable user insights from the beginning.
SMTP check
Verify the mailbox exists by talking to its SMTP server, so you know the address can actually receive mail.
MX record detection
Identify the mail exchange records for the domain to confirm it is set up to handle email at all.
Syntax & registry check
Confirm the address is formatted correctly and check the domain against 68,400 tracked throwaway domains.
How our email checker works
Step 1
You input an email
Step 2
Our engine pings the domain & mailbox
Step 3
You get a detailed validity report
Schedules
Set the date. It verifies before you ask.
Pick any list and any cadence you like — a fixed date, a weekday, a time of day, or a one-off run next Tuesday at 06:00. The engine runs while you sleep and the clean list is waiting before your words begin.
Lists decay about 2% a month. A schedule catches the decay before the send does, and only ever charges for rows it actually checks.
Any date or timePause anytimeResults emailed to the owner
New schedule
august-webinar.csv · 103 rows
Monthly
Same date each month
Weekly
Any weekday you pick
Quarterly
Every three months
One-off
A single future date
Next run 1 Sep 2026, 06:00 · est. 100 credits, duplicates freeOwner gets the export
Feature 01
Email validation
Every address runs syntax, MX, registry and live SMTP checks and comes back with one of five verdicts — deliverable, undeliverable, risky, catch-all or unknown — plus the reason it landed there.
Live SMTP conversation
Reason on every verdict
Confidence level per row
Connects to
REST API & webhooks · CSV, spreadsheet or pasted text
Credits. Nothing expires monthly.
Duplicates and syntax rejects are never charged · 15 free credits on sign-up
Trial
15
free credits
Full engine, every verdict, no card.
1 seat
Pay as you go
$0.008
per credit
Buy 5,000+. Credits do not expire.
1 seat
Team
$0.005
per credit
50,000+ credits, scheduled re-verification, owner-only export.
6 seats
Scale
$0.003
per credit
250,000+ credits, SSO on request, priority queue and support.
10 seats
Your list, fifteen days
Uploads and results are deleted after 15 days by policy, sooner if you delete the job. We do not resell, seed, or mine what you upload.
GDPR-aligned today, SOC 2 next
EU processing region, DPA on request, sub-processor list published. SOC 2 Type II observation window is underway.
Registry, refreshed
68,400 throwaway and temp-mail domains, re-crawled every six hours, plus behavioural detection for generators that spin up new domains hourly.
What do people say about B4Valid?
AR
Alexander Reid
Growth lead
★★★★★
We had 4,000 “valid” addresses from another engine. B4Valid named 380 of them disposable in under a minute. Our bounce rate halved on the next send.
DO
Dana Osei
Developer
★★★★★
Two endpoints, honest docs, and a test key that does not touch the balance. I had signup validation live the same afternoon.
SI
Sana Iqbal
Lifecycle marketer
★★★★☆
The five verdicts are the point. Risky and Disposable get different treatment in our flows instead of both being thrown away.
MV
Marek Varga
CEO
★★★★★
Credits do not expire and the owner controls exports. That was the whole procurement conversation, finished in one call.
Try it before you commit!
One address, one verdict, no account. Fifteen credits when you sign up.
Create free accountResult
Email addresspriya@northgate.co
Did you mean?–
Valid format✓SMTP✓
MX records✓Catch-all✕
RoleTrue
DisposableFalse
FreeFalse
Score0.8
Check fifteen addresses free.
Paste a list, or drop the CSV that came back suspiciously clean somewhere else. Every disposable in it gets named — no card, no call.
Mailbox-level verification with a disposable verdict of its own. 100 addresses in about one second.
© 2026 B4Valid — All rights reserved.Privacy policyTermsGDPR alignedSOC 2 in progress