recycled_mailbox

The mailbox exists now but once answered that it did not

A definitive no-such-mailbox was recorded for the address earlier and the mailbox answers now — the shape of a recycled address, the spam-trap kind included.

risk weight: +30
dataset: mailbox-history
reads from: previously_invalid
verdict reason: recycled_mailbox

What it means

The not-found memory is kept for a year under a keyed hash of the address, fed by the handshake and by bounce reports whose reason reads as user unknown. Only a not-found recorded before this answer counts; a mailbox with no such history reads previously_invalid false.

It reads from previously_invalid and previously_invalid_at and comes with the recycled_mailbox verdict reason, placed after role.

What to do

Do not add it to a campaign list on the strength of one confirmation: a recycled trap is exactly a dead address that came back.

Example response

{
    "email": "[email protected]",
    "deliverable": "risky",
    "reason": "recycled_mailbox",
    "mailbox_exists": true,
    "previously_invalid": true,
    "previously_invalid_at": "2026-05-14",
    "risk_signals": [
        {
            "signal": "recycled_mailbox",
            "weight": 30,
            "dataset": "mailbox-history"
        }
    ]
}

Abbreviated: a real answer carries all 46 fields, listed in the verify-email reference. The risk_signals entry shown is the one this signal adds; the weights of every entry in the list sum to risk_score.

markdown version: /docs/signals/recycled_mailbox.md

recycled_mailbox

What it means

What to do

Example response

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