Confidence Scoring

The confidence field is a detection score from 0–100, built from matched checks. The optional signals array provides context. The score is not a probability or a measured accuracy percentage. Use disposable as the API's final verdict.

How the score is built

Each matched signal contributes a fixed number of points. The points are added together and capped at 100. The disposable boolean flips to true once the total reaches the threshold of 50.

Edge case: confidence ≥ 50 but disposable: false

The no_mx_records signal can raise the score without changing the earlier disposable verdict. For example, high_entropy (+20) plus no_mx_records (+30) can return confidence: 50, disposable: false, and dns: false. This is why comparing the score to 50 does not always reproduce disposable.

Signal	Points
blacklist_exact	100
mx_blacklist_exact	100
mx_ip_blacklist	100
alias_base_exact	100
blacklist_parent	90
keyword_match	80
mx_blacklist_parent	70
pattern_heuristic	60
high_entropy_suspicious_tld	50
free_provider_alias_pattern	35
no_mx_records	30
fresh_domain	25
high_entropy	20
suspicious_tld	15

A single high-confidence signal (any blacklist or exact-alias match) is enough to cross the threshold on its own. Weaker heuristic signals (suspicious_tld, high_entropy, no_mx_records) generally need to combine before a domain is flagged.

Score ranges

Score	Meaning	Typical signals
0	Not disposable	No signals triggered
15–20	Low suspicion	suspicious_tld, high_entropy
25–35	Moderate suspicion	fresh_domain, no_mx_records, free_provider_alias_pattern
50	Likely disposable	high_entropy_suspicious_tld (threshold reached)
60	Probably disposable	pattern_heuristic
70–80	Very likely disposable	mx_blacklist_parent, keyword_match
90–100	Strong detection score	Blacklist/exact-alias matches or several combined heuristics

Choosing a threshold

Start with disposable. If you need a custom rejection or review policy, evaluate it against your own traffic and document the trade-off: a higher score threshold accepts more detected addresses; a lower one challenges more addresses.

A score of 90 or 100 does not prove a blacklist match: several heuristics can add up to that score. Inspect signals if your policy depends on the kind of evidence. Handle DNS and email ownership separately.

See Detection Signals for what feeds each score band.