Understanding your results: valid, risky, invalid and unknown

Every address we check comes back with a status, a score from 0 to 100 and one or more reasons. Here is how to read them.

The four statuses

Valid

The address is well formed, its domain has working mail servers, and nothing suggests a problem. Where a mailbox check was possible and the server confirmed the mailbox, the result is exists. Otherwise valid means the domain can receive mail.

Action: keep and send.

Risky

Probably deliverable, but with a reason for caution:

• disposable: a throwaway inbox
• role_account: a shared address like info@
• possible_typo: the domain resembles a popular one, and a suggestion is provided
• catch_all: the domain accepts any address, so the mailbox can't be confirmed

Action: segment and decide per reason. Fix typos, suppress disposables for trials, and test-send to role and catch-all groups.

Invalid

It will bounce:

• invalid_syntax: not a correctly formed address
• domain_not_found: the domain doesn't exist
• no_mx_records or null_mx: the domain can't receive mail
• mailbox_not_found: the server says the mailbox doesn't exist

Action: delete, or correct if there is a typo suggestion.

Unknown

We couldn't reach a conclusion this time, usually because DNS didn't answer in time.

Action: try again later. Don't delete these. Unknown results are never billed: single and API checks are free, and bulk lists get the credit back when the list finishes.

The score

The score ranks how confident we are that mail will be delivered and welcomed. A clean valid address scores 100. Penalties apply for things like role accounts, typos and disposable domains, with hard caps for the riskiest categories: for example a catch-all domain is capped at 60.

Use it as a dial. A signup form might accept anything above 70 and ask for another address below that.

Reasons are a list

An address can have several. reasons lists all of them and reason is the most important. For example, a possible typo on a domain that also failed DNS shows both.

The mailbox field

• exists: the server accepted the mailbox
• missing: the server rejected it
• catch_all: the server accepts everything
• unknown: the check was attempted but inconclusive
• not_checked: no mailbox check was made, for example for providers that don't answer honestly

mailbox_detail gives a short note like blocked or skipped_provider.

Suggested action

The API also returns suggested_action, a plain recommendation for signup forms: accept, accept_and_confirm (take it, but send a confirmation email first) or reject. Disposable addresses are always reject.

In the CSV

Bulk results add ev_status, ev_score, ev_reason, ev_mailbox and ev_action columns (plus suggestion, provider and flag columns), so you can filter in a spreadsheet. See the cleaning guide for what to do next, or the API docs for the exact fields.