Know an email works before you hit send.
BounceOwl asks the recipient's mail server right now and shows you why: which server answered, what it said, and whether the domain accepts everything. You only pay for real answers.
Live check, no signup, nothing is sent to the address.
$0
for unclear answers
Unknowns, and anything checked on BounceOwl this week, are free.
Never
do credits expire
No subscription. Buy once, use them whenever.
Verifies mail hosted on
- Google Workspace
- Microsoft 365
- Zoho Mail
- GoDaddy
- Proofpoint
- Mimecast
Works with
- ChatGPT
- Claude
- Claude Code
- OpenAI Codex
- Cursor
- Grok
- VS Code
- Hermes Agent
What you never pay for.
The most common complaints about email verifiers are about paying for nothing: unknowns, repeats, credits that run out. So we don't charge for any of it.
Unknown answers
When a mail server won't give a clear answer, you keep the credit. Bad syntax and domains with no mail server are free too.
Some verifiers charge for an unknown and call it a result.
Addresses checked this week
If anyone on BounceOwl checked the address in the last 7 days, you get that result free, with the date it was checked.
Some verifiers charge again for an address checked yesterday.
Unclear catch-all checks
The deeper catch-all check costs 5 credits only when it returns valid or bounce. If it still can't tell, the credits come back.
Some verifiers stop at accept-all and leave you guessing.
Duplicates in your list
The same address twice in one list is charged once. Unused credits come back when the list finishes.
Some verifiers charge per row, repeats included.
Credits you haven't used yet
Credits never expire and there's no subscription. Buy once and use them next week or next year.
Some verifiers expire credits after a year.
100
free credits to start
Sign in with Google. No card, no trial clock.
See why, not just what.
Every result shows which server answered, what it said, what it cost and when it was checked. These are real BounceOwl screens.
Real BounceOwl screens with sample data.
The same checks, for a fraction of the price.
Pay as you go. No subscription, and credits never expire.
Catch-all domains, actually answered.
Many company servers say yes to every address, real or not. Most verifiers stop there and call it accept-all. On B2B lists that can be a big share of the addresses.
- 1
Spot it
The regular check also tries a made-up address at the same domain. If the server accepts that too, the domain is catch-all.
- 2
Remember it
We note the domain, so the next address there is marked catch-all right away instead of asking the same question again.
- 3
Answer it
When you choose to, the catch-all check digs past the server's blanket yes and comes back with valid or bounce. If it still can't tell, the result is unknown and free.
Verify from your AI assistant, or your own code.
BounceOwl runs as an MCP server and a REST API, so ChatGPT, Claude, Codex, Cursor or your app can check addresses with the same evidence and the same free unknowns.
Connect BounceOwl to your AI assistant with one API key. Ask it to check a few addresses, clean a list or explain a catch-all result, in plain words. Same credits, same evidence, same free unknowns.
Works today
- ChatGPT
- Claude.ai and Claude Desktop
- grok.com
- Claude Code
- OpenAI Codex
- Cursor
- VS Code / GitHub Copilot
- Hermes Agent
- Grok Build CLI
- xAI API (Grok models)
- Zed
- Cline
Check these leads and tell me which are safe to email: maya.chen@lumenforge.io, d.okafor@harborlane.com, j.ortiz@quarrybank.co
maya.chen@lumenforge.io is valid: the Google Workspace server accepted the mailbox.
d.okafor@harborlane.com is on a catch-all domain. Want me to run the catch-all check (5 credits)?
j.ortiz@quarrybank.co would bounce: the server says the mailbox doesn't exist.
Example conversation with made-up addresses.
Questions people ask.
What does real-time mean here?
Each check opens a live connection to the recipient's mail server and asks whether the mailbox exists. If anyone on BounceOwl checked the same address in the last 7 days, we show that result with its date instead of asking again, and it's free.
Does the person get an email when I check them?
No. The check stops before any message is sent, so nothing lands in their inbox.
Do I pay if someone else already checked the address?
No. If anyone on BounceOwl checked the same address in the last 7 days, you get that result free, with the date it was checked. Nobody can see who else checked it.
Why are unknown results free?
Some servers don't answer or slow verifiers down on purpose. When we can't get a real answer, you shouldn't pay for it.
What is a catch-all domain?
A domain whose mail server accepts every address, real or made up, and sorts things out later. A normal check can't tell real mailboxes apart there, which is why many verified lists still bounce.
Do I need the catch-all check on every address?
No. Run the regular check on your whole list, then run the catch-all check only on the addresses marked catch-all.
Can I use it from my own app or AI assistant?
Yes. Create an API key in your account to call the API, or use the same key to connect the BounceOwl MCP server to Claude Code, Cursor or another MCP client.
Check your next list before it costs you a domain.
100 free credits with Google sign-in. Pay as you go after that, and credits never expire.