Email Verification API

The recipient path accepted the probe when the call ran. Accept the signup, write the contact, or queue the message, subject to whatever consent rules your product enforces.

The free email verification api returns the same status field on the free tier as on paid volume, so behaviour you test with free credits is the behaviour you ship.

A permanent failure from the API means the address will hard-bounce. In a signup form, show the field again with the API reason code. In a background job, suppress the record rather than deleting the original value.

Never auto-correct the domain. A verification api can tell you an address fails; it cannot tell you which address the person meant.

Risky means the mailbox may accept mail while carrying a flag your product might care about. Read the reason codes: a disposable provider on a paid signup is a very different problem from a role address on a support form.

Encode the policy once, at the point where you call our free email verification api, so every surface in the product treats the same API flag the same way.

The receiving provider gave the API an answer that proves nothing. Queue the address for a later API call rather than blocking the user or writing a false negative into your database.

The real-time email verification API used inside a signup flow should degrade gracefully here: let the user through, verify again asynchronously, and act on the second API result.

An accepting mailbox says nothing about who controls it, where they work, or whether they agreed to be contacted. Shared aliases, forwarded addresses, and stale enrichment all produce deliverable API results attached to the wrong person.

Use first-party data for identity and keep consent in your own system of record. No verification api can supply either.

SMTP acceptance describes the recipient path at the moment of the API call. Whether your campaign reaches the inbox depends on sender reputation, authentication, content, and complaint history — all sender-side factors the API never observes.

Verification removes address-level failures. Deliverability of the message itself is a separate programme with separate metrics.

A catch-all domain accepts every local part, so no free email verification api can prove that one guessed address exists there. The API returns the flag precisely so your code does not have to infer it.

Route catch-all results to review rather than folding them into deliverable, especially on B2B lists built from name patterns.

Mailboxes are closed, aliases retired, and domains migrated every day. The API reports what was true during the call, and that fact ages from the second the API responds.

Store the checked-at time next to the status so downstream systems can decide when the evidence is too old to act on.