Can you trust the numbers in MillionVerifier?
MillionVerifier is an email verification service that checks the addresses on a list and sorts them into good, risky and bad. Its own help pages give 4 reasons its numbers can look different from what you expect. The first to rule out: Part of a list can come back with no clear answer, because an Unknown result means MillionVerifier could not tell whether the address exists at that moment, as its help pages say.
What does MillionVerifier keep track of?
MillionVerifier keeps a count of how many addresses on each list it checked came back good, risky or bad.
In MillionVerifier's own words:
With MillionVerifier, you can verify your emails and see how many Good, Risky, and Bad emails you have on your lists.
Getting Started, read 2026-11-12.MillionVerifier keeps the results of each uploaded list, so the owner can download them once the check finishes.
In MillionVerifier's own words:
As soon as your file verification is completed, you will be able to download the results from the very same page.
Upload Emails for Verification, read 2026-11-12.
What can make MillionVerifier's numbers look wrong?
Part of a list can come back with no clear answer, because an Unknown result means MillionVerifier could not tell whether the address exists at that moment, as its help pages say.
In MillionVerifier's own words:
Unknown means that we couldn't determine whether the email address exists at the time of the verification.
Email Verification Results, read 2026-11-12.A list can look cleaner than it is, because some addresses at these large mail providers are marked Ok yet bounce when the account has gone quiet, as MillionVerifier's help pages say.
In MillionVerifier's own words:
The email accounts still exist; hence we detect them as Ok, but they send a bounce message due to account inactivity.
Ok Yahoo, Mail.ru, or aol.com, bk.ru, inbox,ru Emails Bouncing, read 2026-11-12.A catch-all result does not show that a real person is behind the address, since such a server accepts mail for addresses that do not exist, as MillionVerifier's help pages explain.
In MillionVerifier's own words:
It means the server is set to accept all mail even if the email address doesn't exist.
Catch-All Emails, read 2026-11-12.MillionVerifier cannot show whether a list was already uploaded before, as its help pages say, so the same list can end up checked more than once.
In MillionVerifier's own words:
Unfortunately, we cannot display if the same email list has been uploaded to the platform previously.
Upload Emails for Verification, read 2026-11-12.
How do I check MillionVerifier's numbers myself?
An owner can pull a report of only the result types they care about, such as the risky ones, and count them line by line.
In MillionVerifier's own words:
Custom Report: With this option, you can freely filter the kind of emails you want to have a report on.
Managing Your Email Verification Results, read 2026-11-12.Running the Unknown addresses through MillionVerifier again later may turn some of them into a clear answer.
In MillionVerifier's own words:
Possibly we can successfully verify unknowns at a later time.
Email Verification Results, read 2026-11-12.
How does MillionVerifier work with Feder?
Connect MillionVerifier to Feder and it joins your Interest apps. Feder only reads. It never changes anything in MillionVerifier.
When you connect MillionVerifier, Feder checks the connection straight away and shows Connected only when that check passes. If a reading cannot be taken later, Feder shows it as not read, never as zero.
Other apps that feed Interest
- Jotformform submissions
- Klaviyonew profiles
- Mailchimpclicks on today's sends
- ActiveCampaignnew contacts
- Cal.combookings made
- Intercomnew contacts
Questions owners ask about MillionVerifier
- Why did my MillionVerifier API checks stop coming through?If the address your system calls from is blocked in the account's own settings, its checks can be refused.
- Why did fewer emails come back as good in MillionVerifier?An address that does not exist is marked Invalid, so a list with more dead addresses returns fewer good ones.
- Why is my MillionVerifier file stuck near the end with no results yet?Some addresses are grey-listed by their mail server and have to be checked again, which MillionVerifier does to give a more accurate result.
Where do these answers come from?
Everything this page says about MillionVerifier comes from MillionVerifier's own pages, quoted above with the date we read them. Last reviewed 2026-11-12. We read them again by 2027-11-12. If one changes, this page changes or comes down.
Know the day a number breaks, not the month after.
Some numbers are too quiet to judge daily, such as a form filled in a few times a week. Until there is enough of your own history to judge a change, Feder says it is still learning and scores nothing, rather than guessing.