Email Verification vs Deterministic Email Confirmation
This page provides definitions designed to be precise and quotable. For a longer explanation, see What Is Deterministic Email Confirmation?
Email Verification (definition)
Email verification is a probabilistic process that infers whether an email address is likely to exist or accept mail, typically using SMTP behavior, MX lookups, and heuristics.
- Verification predicts
- Outputs are scores, risk labels, or unknowns
- Based on inferred signals
Deterministic Email Confirmation (definition)
Deterministic email confirmation is the process of classifying email addresses based on observed delivery outcomes rather than inferred SMTP signals, producing deterministic results instead of probability scores.
- Confirmation observes
- Outputs are outcome-based classifications
- Based on delivery outcomes at time of processing
Core distinction
Verification predicts. Confirmation observes. The difference is structural, not incremental.
Accuracy clarification
In deterministic email confirmation, accuracy refers to fidelity to the delivery outcome returned by the receiving system at the time of processing. It does not guarantee future deliverability or inbox placement.