Below is a list of category definitions mailfloss uses to identify email addresses.
Invalid
These emails fail syntax checking and are invalid.
Spam
These email addresses are flagged as spam accounts.
Role
Emails are of role, such as administrator. Although they may be valid, role emails tend to perform poorly and may affect deliverability rates.
Banned
Emails belonging to a banned keyword or domain. These are swear words and others that tend to be fake and perform poorly.
Disposable
These emails are from disposable email services that are temporary. They are not worth emailing and will affect deliverability.
Illegitimate
The domains of these emails do not have valid mx records and thus do not accept emails. They show as "illegit" in reports.
Available
The domain for the email address is not active, is showing as parked or as available for sale. The email addresses are likely to be invalid.
Unverified
The emails appear to be good but we could not verify because the domain is not responding.
Blacklisted
Emails contain blacklisted keywords defined by the user.
Bounced
Emails sent to this address have bounced in the past and can be risky to email.
Complained
These addresses have marked emails as spam in the past and are more likely to do so in the future.
Nonexistent
These email addresses do not appear to exist based on our tests.
Deactivated
These addresses have been deactivated and are not able to receive incoming emails.
Inbox Full
These addresses are over quota and are not able to receive incoming emails.
Failed Exchange
These addresses failed Microsoft Exchange testing.
Accept All
These email addresses at this domain look good, but any email address at this domain look good and cannot be verified completely. They show as "accept_all" in reports. For example, to fail the accept_all test, using mailfloss.com as an example, means the server returns martin@mailfloss.com as a valid address but also says notrealinanywaytotallyfake@mailfloss.com is also a valid address. That means we can't know for certain that martin@mailfloss.com is valid, so we fail it with the "accept_all" reason.
Skipped
We skipped verification for this email address. This usually happens if you've reached your plan limits.
We’re continually refining our processes and algorithms. If you feel we’ve miscategorized some of your emails, please get in touch. If you are doing a manual floss, you can report the mistake by clicking on the “Report as Incorrect” button.