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Glossary

What is a spam trap?

A spam trap is an email address that exists only to catch senders who mail people who never asked for it. Some were never published or opted in; others are abandoned mailboxes a provider has reactivated to listen for this.

Also known as Honeypot address · Pristine trap · Recycled trap

The two kinds, and they arrive differently

A pristine trap is an address that was never used by a person and never subscribed to anything. It is seeded where only a scraper would find it. Mail arriving at one is close to proof that the sender harvested addresses rather than collecting them, because there is no honest route by which it could be on a list.

A recycled trap is a real mailbox that was abandoned, left to hard-bounce for a period, and then reactivated by the provider to listen. It is the more common one, and it is the one that catches senders who are not malicious — merely not processing their bounces. Mail arriving at a recycled trap says the sender kept mailing an address that had already been refused.

Both are operated by anti-abuse organisations and mailbox providers rather than published anywhere. That is the point: an address you could look up would not work.

How they get onto a list

Scraping addresses off web pages indiscriminately. Buying or renting a list. Importing an old export and mailing it without re-verifying. Never suppressing hard bounces, so an address that died two years ago is still being mailed when the provider turns it back on. Accepting any typed address at signup without confirmation.

What these have in common is that the sender has no record of the recipient agreeing. A trap is not really a separate hazard — it is the same list-quality problem, measured by somebody who is keeping score.

How VerifyInbox handles it

VerifyInbox does not detect spam traps, and no verifier reliably can. A pristine trap is a working mailbox on an ordinary domain; over SMTP it is indistinguishable from any other deliverable address, and a tool claiming otherwise is either guessing or relying on a list that anybody could evade. What verification genuinely does is remove the addresses that are already refusing mail — which is exactly the population recycled traps are drawn from. Suppressing hard bounces the first time is the mechanism that keeps them off a list, and it is a mechanism rather than a claim.

What actually keeps them off a list

Collect addresses rather than harvesting them, and keep the record of where each one came from. Confirm addresses at signup. Suppress every hard bounce permanently the first time it happens, which is the single control that stops recycled traps. Never mail a list you did not build without re-verifying it, and re-verify anything you have not mailed in months.

Google’s sender guidelines reduce to the same instruction from the other direction: send only to people who asked, make unsubscribing easy, and act on the signals you are given.

Why we publish no numbers here

You will find confident statistics about what proportion of lists contain traps and how many complaints one costs you. We have not measured any of that, and the organisations that could measure it deliberately do not publish operational detail, because publishing it is how you make a trap useless. A number here would be invented, and inventing one on a page about data honesty would be an odd way to argue the case.

Check whether an address still accepts mail before you send to it. No account, and it runs now: Email verifier

Related terms

Sources

Primary sources checked 11 September 2026. If something here is out of date, tell us and we will correct it.

Spam trap: questions

What is a spam trap?

An address that exists only to catch senders mailing people who never asked. Some were never used by anyone and are seeded where only a scraper would find them; others are abandoned mailboxes that a provider left to bounce and then reactivated to listen.

What are spam traps and why should I avoid them?

They are addresses operated by anti-abuse organisations and mailbox providers to identify senders who harvest addresses or ignore their own bounces. Mail arriving at one is treated as evidence about your whole list, so the cost is to sender reputation rather than to a single campaign.

Does the tool identify spam traps?

No, and we will not claim to. A pristine trap is a working mailbox on an ordinary domain, indistinguishable over SMTP from any other deliverable address. What verification does is remove addresses that are already refusing mail, which is the population recycled traps are drawn from.

Can a catch-all email ever be classified as a spam trap?

The two are unrelated properties and an address can be both. A catch-all domain accepts everything, so acceptance there tells you nothing either way — which is exactly why a catch-all result is reported as unknown rather than deliverable, and why bulk-sending to a catch-all-heavy list is the riskiest thing on this page.

Verify an address against the real mail server

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