Unknown Results
Unknown means that we couldn't determine whether the email address exists at the time of the verification. Possibly we can successfully verify unknowns at a later time. That is why it can be RISKY to send an email to these addresses.
Why is it not recommended to select Unknown emails for EverClean?
There are many reasons why we can't tell whether an email address is valid or not. In this case, we say the result is Unknown.
It is possible that the verification result of an email address is Unknown, but it is a Valid email. It can cause severe damage to your email lists if you select to remove Unknown emails from your email lists with EverClean, as you might remove Valid addresses from your lists caused by some external error.
That is why it is NOT recommended to select Unknown emails in your EverClean service.
