Spam trap
A spam trap is an address that exists only to catch senders who mail people who never asked. Some are addresses created purely as bait; others are abandoned mailboxes that a provider has repurposed after years of inactivity. Mail to one is strong evidence that a list was bought, scraped or never cleaned, and the penalty is applied to the sender.
At a glance
- Category
- Deliverability
- Pristine trap
- An address created as bait and never used by a person
- Recycled trap
- An abandoned mailbox repurposed after long inactivity
- Typosquat trap
- A misspelling of a large provider's domain
- Evidence of
- A list that was bought, scraped or never cleaned
- Cannot be
- Removed by asking — you will not be told which address it was
How it works
Anti-abuse organisations and mailbox providers seed addresses where a harvester will find them and nowhere a person would, so any mail arriving is by definition unsolicited. Separately, providers take mailboxes that have been dead for a long time, let them bounce for a period, and then quietly start accepting mail again — at which point anything still arriving proves the sender never processed the bounces. Hits are fed into reputation systems and blocklists, usually without any notification.
Why it matters
A trap hit is one of the few signals that is treated as close to proof rather than as evidence to be weighed, because there is no innocent way for that address to be on a list. Recycled traps also punish the specific failure of ignoring hard bounces, which is why suppression matters as a process rather than as a tidy habit. The practical consequence is that you cannot investigate a hit: nobody will tell you which address it was.
Example
A company imports a list of conference attendees collected by a third party. Several of the addresses were never typed by a person and exist only to catch this. The first campaign reaches them, a blocklist operator records the hits, and within days the sending domain is listed and placement collapses at several providers. Removing the imported segment stops further hits, but the listing takes weeks to age out.
Common mistakes
- 01Buying or renting a list, which is the single most reliable way to reach a pristine trap.
- 02Ignoring hard bounces, which leaves the exact addresses that become recycled traps on your list.
- 03Mailing a segment that has been dormant for years to reactivate it, when dormant is the state a recycled trap comes from.
- 04Asking a provider which address was the trap, which nobody will answer because doing so would tell abusers what to remove.
Related terms
Frequently asked questions
How do I know whether I have hit a spam trap?
You usually cannot see it directly. The symptoms are a sudden fall in placement or an appearance on a blocklist, with no matching rise in bounces or complaints to explain it.
Can I get a trap address removed from my list?
Not by asking, because you will never be told which address it is. The workable approach is to stop mailing the segment that caused the hits and to process hard bounces properly from then on.
Does double opt-in prevent trap hits?
It prevents most of them, because a trap address will never confirm a subscription. It does not help with recycled traps on a list you built before you started confirming.
Sources
Last updated 16 September 2026.
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