Verification statuses & accuracy
What are the possible verification statuses for an email?
What are the possible verification statuses for an email?
Each status shows how deliverable an email address is:
Valid: confirmed as safe to send.
Invalid: doesn't exist or rejects mail.
Accept-all: the domain accepts all emails, so results can vary.
Disposable: a temporary or fake address.
Unknown: the server didn't respond or blocked verification.
For the full breakdown and color codes, see What are the possible verification statuses for an email?
Does an email marked as "valid" have no chance of bouncing?
Does an email marked as "valid" have no chance of bouncing?
Email verification is never 100% certain, since a mailbox can change status at any time after it's checked.
That said, a "Valid" status means the address passed every check Hunter runs and is safe to use.
What does "Accept-all" mean?
What does "Accept-all" mean?
An "Accept-all" status means the domain's mail server is configured to accept every email sent to it, even if the specific mailbox doesn't exist. This makes it impossible to confirm deliverability with full certainty.
When you see this status, check the Confidence Score and prioritize sending to addresses scoring above 85%.
Learn more in What does an "Accept-all" email status mean?
Why can't some emails be verified?
Why can't some emails be verified?
Some mail servers block verification attempts or don't respond, which makes it impossible to confirm the mailbox. This results in an "Unknown" status, and no credits are used when this happens.
See Why some emails can't be verified and how to fix email verification issues for every possible cause and how to fix it.
Why did a "Valid" email bounce anyway?
Why did a "Valid" email bounce anyway?
A small percentage of “Valid” addresses can still bounce. This is outside of our control, as mailboxes can be deleted, become full, or rejecting emails after Hunter has verified them. Bounces can also happen if your sender email address has deliverability issues.
We always recommend verifying your recipients shortly before reaching out.
If you’re seeing bounces on emails verified on the same day, that’s unusual. In that case, please contact our support team at contact@hunter.io and share the specific email addresses along with the bounce messages, so we can investigate further. Since this may be related to your account’s deliverability.
How is the Confidence Score calculated?
How is the Confidence Score calculated?
Hunter estimates the Confidence Score from patterns like how the address's format matches known naming conventions at that domain, and whether we've seen it engage successfully elsewhere. It's not a live mailbox check.
Using the Email Verifier
Can I verify webmail addresses?
Can I verify webmail addresses?
Yes — webmail addresses (Gmail, Outlook, Yahoo, and similar providers) can be verified with both the Email Verifier and the Bulk Email Verifier, the same way as any other address.
Can I verify a list of emails all at once?
Can I verify a list of emails all at once?
Yes, you have a few options for verifying entire lists:
Upload a CSV or TXT file to the Bulk Email Verifier and download the results.
Select and verify existing leads directly from the Leads section.
Turn on verification while importing a list of leads into Hunter.
Are emails returned in Hunter already verified?
Are emails returned in Hunter already verified?
Emails found via the Email Finder or Bulk Email Finder are already verified, so they're safe to use for outreach right away.
Emails from Domain Search, Bulk Domain Search, and Discover are mostly verified too — you'll see a verification status. If an email hasn't been verified recently, you'll see an option to verify it directly within those tools. Once revealed and saved to your leads, these emails return the last verification status and a last verification date. We still recommend running a verification on them before reaching out.
Can I verify emails through the API?
Can I verify emails through the API?
Yes — Hunter's Email Verifier is available as an API endpoint (GET https://api.hunter.io/v2/email-verifier), so you can check a single email at a time and get back the same status (Valid, Invalid, Accept-all, etc.) It's rate-limited to 10 requests/second, and doesn't support batch requests in one call. If you're verifying regularly at volume, the Data Platform plan is built for this kind of usage.
Learn more about our available API endpoints here.
How can I verify emails in Hunter
How can I verify emails in Hunter
There are a few ways, depending on how many emails you need to check:
Single email: use the Email Verifier — paste in an address and get an instant result.
A list of emails: upload a CSV or TXT file to the Bulk Email Verifier and download the results once it's done.
Leads already saved in Hunter: select them in the Leads section and verify directly from there.
While importing a list: turn on verification as part of the import process, so leads are verified as they're added.
Via API: call the Email Verifier endpoint programmatically if you want to verify emails from your own app, CRM, or workflow.
Emails found through the Email Finder or Bulk Email Finder come already verified, so you don't need to re-check those separately.
What checks are done during verification?
What checks are done during verification?
The Email Verifier runs a series of checks on each address before returning a result:
Valid format — the address is structured correctly (e.g.
name@domain.com).Gibberish check — flags addresses that look randomly generated (e.g.
1e49cs1pb6@company.com).Disposable address — checks if the domain is a known temporary/throwaway email service; these can't be verified.
Webmail detection — flags whether it's a webmail address (Gmail, Yahoo, etc.).
MX records — confirms the domain actually has a mail server set up to receive email.
SMTP server connection — confirms Hunter can connect to that mail server.
SMTP check — checks whether the specific mailbox exists, without actually sending an email. If the server blocks this step, the result comes back "Blocked."
Accept-all check — flags if the domain accepts all incoming mail regardless of whether the mailbox exists, which limits how certain the result can be.
Credits & usage
How many credits are used to verify an email?
How many credits are used to verify an email?
All-in-One Outreach plans: 0.5 credits per verification.
Data Platform plans: 1 credit per verification.
Unknown results: no credits deducted.
For a full breakdown across all Hunter tools, see How do credits work in Hunter?
Will I be charged to verify the same email again?
Will I be charged to verify the same email again?
No — verifying the same email again is free within a certain window, though the exact rule depends on your plan:
All-in-One Outreach, monthly plans: free if repeated within the same billing period.
All-in-One Outreach, yearly plans: free if repeated within the same calendar month.
Data Platform plans: free if repeated within the same calendar month.
Outside that window, verifying the same email again does use credits again.
Duplicates are also tracked at the team level (if a teammate already verified it, you won't be charged either), but bulk CSV uploads are the exception — Hunter doesn't detect duplicates across separate bulk files, so verifying the same email in two different bulk uploads charges credits both times.
What is Automatic leads verification?
What is Automatic leads verification?
Automatic lead verification re-verifies your saved leads found through Hunter every month, once they've been verified for the first time — at no extra cost and with no additional credits used.
It's available on paid plans (Starter, Growth, Scale, and Enterprise) and runs automatically in the background. Each time a lead is re-verified, its "Verification Date" updates in your Leads dashboard, so you always know how current the data is.
See Automatic Leads Verification for more detail.