Hunter’s Email Verifier helps you check if an email address is valid, risky, or invalid before sending campaigns.
This FAQ covers the most common questions about verification statuses, color codes, and confidence scores — with links to related guides for more detailed explanations.
📨 Understanding Email Verification
What is an Email Verifier?
What is an Email Verifier?
An email verifier checks whether an email address is valid and deliverable by analyzing its format, domain records, and mail server response.
Using an email verification tool helps you reduce bounces, protect your sender reputation, and improve deliverability.
Why should you verify email addresses?
Why should you verify email addresses?
Verifying email addresses is essential for maintaining a healthy sender reputation and preventing wasted effort on invalid or fake contacts.
By confirming that each address is real and active, you ensure your emails reach genuine recipients, reduce bounce rates, and improve engagement.
Regular email verification helps you build a clean, high-quality email list, leading to better deliverability, higher open rates, and more effective marketing or sales campaigns.
How does Hunter’s Email Verifier work?
How does Hunter’s Email Verifier work?
Hunter verifies both professional and webmail addresses through several in-depth checks (format, domain, MX records, SMTP connection, and more).
You can verify single emails in the Email Verifier, entire lists in the Bulk Email Verifier, or automate checks through the Email Verifier API.
💡 See What checks are performed during email verification? for a detailed breakdown of each step.
How often should I verify my email list?
How often should I verify my email list?
You should verify your email list regularly before contacting leads to ensure all addresses are valid and deliverable. Email data changes constantly as people switch jobs or providers, and sending to outdated addresses can negatively affect your deliverability and sender reputation.
With Hunter, most email addresses are already verified when you find them, and each one includes a clear verification status (Valid, Accept all, Unknown, or Invalid).
When leads are saved in your Leads section, you’ll also see the last verification date. Hunter automatically re-verifies your saved leads every month, free for users on All in One Outreach paid plans, keeping your email data accurate and ready for outreach.
💡 Learn more on why regular email verification is important in this blog post.
🔍 Verification Process & Checks
What checks are performed during the email verification process?
What checks are performed during the email verification process?
Hunter’s Email Verifier runs several technical checks to confirm whether an email address is valid and deliverable — without ever sending an actual email.
These include validating the address format, domain records, and mail server response, among other steps.
To learn more about each individual check, see What checks are performed on an email with the Email Verifier.
What do the verification statuses mean (Valid, Invalid, Accept-All, Disposable)?
What do the verification statuses mean (Valid, Invalid, Accept-All, Disposable)?
Each status shows how deliverable an email address is:
Valid: confirmed as safe to send.
Invalid: does not exist or rejects mail.
Accept-All: domain accepts all emails; results can vary.
Disposable: temporary or fake address.
Unknown: server didn’t respond or blocked verification.
For full details, see What are the possible verification statuses for an email?.
What do the colour codes in Hunter’s Email Verifier represent?
What do the colour codes in Hunter’s Email Verifier represent?
Each verification status is paired with a color:
Valid - Green: email addresses that can receive emails and can be used safely.
Accept all - Yellow: email addresses that have email servers that accept any type of email sent to them. Using this type may lead to bounces. Learn more about accept all emails.
Invalid - Red: email addresses that can't receive emails, are inactive and shouldn't be used.
Disposable - Blue: email addresses which are temporary emails that shouldn't be used for cold outreach.
Unknown - Grey: email addresses that couldn't be verified.
What is a Confidence Score?
What is a Confidence Score?
The Confidence Score estimates how likely an email is to be valid, based on available data.
It’s most useful for Accept-All emails, where deliverability is uncertain.
For other statuses, rely on the verification status instead of the score when deciding whether to send.
More details can be found in the accept all emails article.
Why can’t certain email addresses be verified?
Why can’t certain email addresses be verified?
Some servers block verification attempts or don’t respond, making it impossible to confirm the mailbox.
This results in an “Unknown” status — no credits are used.
💡 Learn more about all the possible cases where emails can’t be verified here.
📊 Accuracy & Results
Can verification results change over time?
Can verification results change over time?
Yes. Domains and mail servers can change, meaning a previously valid address might later become invalid or Accept-All.
Hunter automatically re-verifies saved leads for all users on paid All in one outreach plans every month to keep data accurate.
What should I do with invalid or accept-all/risky emails?
What should I do with invalid or accept-all/risky emails?
Invalid: don’t use these emails — they’ll bounce and harm your reputation.
Accept-All: proceed carefully and prioritize those with a Confidence Score above 85%.
For more detail, read the Ultimate Guide to Accept-All (Catch-All) Emails.
What does “Unknown” status or error mean in verification results?
What does “Unknown” status or error mean in verification results?
“Unknown” means Hunter couldn’t confirm the mailbox’s existence due to blocked or unresponsive servers.
You can retry later if it’s a temporary issue.
No credits are used for these verifications.
💡 We have written a full guide on Why some emails can’t be verified and how to fix email verification issues.
⚙️ Using the Tool
How to verify a single email address in Hunter?
How to verify a single email address in Hunter?
Single email: use the Email Verifier.
Multiple emails: use the Bulk Email Verifier.
Saved leads: verify directly in your Leads section.
Automated verification: integrate through the Email Verifier API.
Where can I view or export my verification results?
Where can I view or export my verification results?
You can download results as a CSV from the Bulk Email Verifier or export verified leads from the Leads section.
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 verification credit per email.
Unknown results: no credits deducted.
To learn more, see our detailed guide: How credits work in 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 you can safely use them for your outreach campaigns.
Emails returned from the Domain Search, Bulk Domain Search or Discover are also mostly verified. When an email has been verified, you’ll see a verification status assigned to it, such as Valid or Accept All, for example. You also have an option to filter your leads by verification status.
If an email hasn’t been verified recently, you’ll see an option to “Verify email addresses” directly within the Domain Search or Discover functionalities.
Can I integrate Hunter’s Email Verifier with other tools?
Can I integrate Hunter’s Email Verifier with other tools?
Yes, Hunter offers native integrations with CRMs and marketing platforms like HubSpot and Salesforce, as well as Zapier and Make for automations.
If you want to connect it to your own systems or custom workflows, you can use the Email Verifier API, which allows full programmatic access to Hunter’s verification features. You can learn more about the API in the dedicated documentation.