Spam trap
spamtrap / spam traps / pristine spam trap / recycled spam trap
A spam trap is an email address kept to catch senders who mail people without permission. Nobody ever signed up with it, or its owner abandoned it long ago, so mail arriving there points to a problem with how a list was built. Hitting traps can get your email blocked.
Spamhaus, which publishes widely used email blocklists, asks senders to view spamtraps as proof of a data collection or hygiene issue. A trap exists to expose senders who add addresses to their lists without permission. Mail landing in one says something about the list the message came from.
The trap types show where a list went wrong. A pristine trap was never given to a real person or published on a website, yet it receives mail. A seeded trap is placed where only a scraper would find it, such as in a page's source code. A dead address trap was once a real mailbox that rejected mail for a period, often 12 months or more, before being quietly switched back on.
Typo domain traps sit at lookalike domains such as yaaho.com or homail.com. Spamhaus notes these can hold a lot of real mail and are weighted accordingly, so a stray typo carries less weight than a scraped list.
Trap owners keep their addresses secret. Spamhaus gives two reasons: the traps are part of how filtering works, and a sender who finds one tends to delete that address and change nothing else. Microsoft moved the same way. Its Smart Network Data Services report stopped including trap hit counts on July 22, 2026, to protect its anti-abuse systems.
In practice
A clinic imports 4,000 addresses collected at trade shows over several years and sends a newsletter. Hundreds bounce straight away. Among the rest are old addresses that bounced for a year and now accept mail as traps. The clinic never learns which ones. It sees mail landing in spam or being refused, and the lasting fix is to mail only people who recently asked to hear from it.
Not the same as
- Spam complaint rate
- A complaint is a person pressing report spam. A trap hit involves no person at all, only an address that should never have been on the list.
Why it matters to you
A trap hit is evidence about list building, and the usual causes are buying lists, scraping addresses and mailing contacts long gone quiet. Spamhaus warns against hunting for the traps, because removing them only treats the symptom. The list practice that collected them keeps collecting more.
What to ask or check
- 01Where did every address on this list come from, and when did each person last opt in?
- 02Does the email system stop mailing an address after it hard bounces?
- 03Has any part of this list been bought, rented or scraped?
What people get wrong
That a list cleaning service can find and strip out every trap. Trap owners keep them secret, and Spamhaus says removing traps only treats the symptom of a list problem.
Red flags
- A list bought, rented or scraped from a third party.
- Addresses that hard bounced still being mailed months later.
- A plan to find the trap addresses instead of fixing how addresses are collected.