Unfortunately we cannot do that. We validate from a neutral point of view. And that setting that you mention it is made on the server, there isn't a way to verify if that set exist only if you send an email to it. That is the only way to know that!
Can a subscription be used to provide services to a customer base? If so, can unique API keys and Integrations be used so that usage for each customer can easily be identified.
Also, Is there a native Constant Contact integration? If not, why?
Yes, we do have a subscription option if you are interested; however, this code that you can buy from AppSumo is for a one-time payment. Also, our service is meant for customers and organizations.
As for the API keys, yes, you can create API keys to add where you want and can see the usage for each key.
Also, we do have an integration with Constant Contact, as you see here:...
I run cold email campaigns using 28 inboxes with Instantly, and I’m considering using ZeroBounce primarily for email deliverability monitoring.
I want to clarify:
If I run the Inbox & Server Test for each inbox once or twice a month (28 inboxes total), how many credits does that consume per test?
Does each inbox test cost 1 credit, or is it more?
Is this Appsumo deal sufficient for ongoing deliverability checks (SPF/DKIM, blacklist, inbox placement) across 28 inboxes, or would I need to purchase extra credits?
The ZeroBounce AppSumo listing provides 24,000 credits to validate your email address list (one credit per email address validation).
With a ZeroBounce account, you'll receive 1 Inbox Placement test every month (plus 1 Email Server Test, 1 Blacklist Monitor and 10 Email Finder queries).
Based on what you're looking for (2 Inbox Placement and Server Tests per month, and DMARC...
Q: How many emails can you verify with 24,000 credits?
How many emails can you verify with 24,000 credits?
support-team
Aug 22, 2025A: Hello,
Thank you for your question!
You can validate 24,000 emails, 1 credit = 1 email.
I hope this helps!
Share ZeroBounce Email Verification
Q: Can your tool detect email addresses that only accept internal emails and block external senders?
support-team
Aug 21, 2025A: Hello,
Thank you for your request!
Unfortunately we cannot do that. We validate from a neutral point of view. And that setting that you mention it is made on the server, there isn't a way to verify if that set exist only if you send an email to it. That is the only way to know that!
I hope this helps!
Share ZeroBounce Email Verification
Q: Is this meant for org use, or customers too?
Can a subscription be used to provide services to a customer base? If so, can unique API keys and Integrations be used so that usage for each customer can easily be identified.
Also, Is there a native Constant Contact integration? If not, why?
support-team
Aug 4, 2025A: Hello,
Yes, we do have a subscription option if you are interested; however, this code that you can buy from AppSumo is for a one-time payment. Also, our service is meant for customers and organizations.
As for the API keys, yes, you can create API keys to add where you want and can see the usage for each key.
Also, we do have an integration with Constant Contact, as you see here:...
Share ZeroBounce Email Verification
Q: Can i buy 2 codes and get 48,000 verifications
Anne_ZeroBounce
Jul 28, 2025A: Yes, you can purchase more than one code and stack the codes to get more email verification credits for on the ZeroBounce platform.
Share ZeroBounce Email Verification
Q: Email Deliverability
Hi there,
I run cold email campaigns using 28 inboxes with Instantly, and I’m considering using ZeroBounce primarily for email deliverability monitoring.
I want to clarify:
If I run the Inbox & Server Test for each inbox once or twice a month (28 inboxes total), how many credits does that consume per test?
Does each inbox test cost 1 credit, or is it more?
Is this Appsumo deal sufficient for ongoing deliverability checks (SPF/DKIM, blacklist, inbox placement) across 28 inboxes, or would I need to purchase extra credits?
Anne_ZeroBounce
Jul 21, 2025A: Hello!
The ZeroBounce AppSumo listing provides 24,000 credits to validate your email address list (one credit per email address validation).
With a ZeroBounce account, you'll receive 1 Inbox Placement test every month (plus 1 Email Server Test, 1 Blacklist Monitor and 10 Email Finder queries).
Based on what you're looking for (2 Inbox Placement and Server Tests per month, and DMARC...
Share ZeroBounce Email Verification
Would love a answer here