What is a trap cluster?
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Imagine hitting ten spam traps at the same time instead of one. That's a trap cluster. It's a group of fake addresses on the same domain, or acquired from the same source, that activate together.
This happens when your list came from one bad source. You bought an old mailing list. You scraped addresses from the same website. You imported a batch from one data broker. The traps inside all hit your sends around the same timeframe. Clustered hits are much worse than scattered hits because they tell blocklist operators you didn't just make a random mistake. They signal systemic sourcing problems.
Here's why it escalates so fast. When blocklist operators see a cluster, they interpret it as intentional or negligent bulk sending. They can list your domain quickly and aggressively. One trap might be forgivable. Ten at once. That's a pattern.
Next: Review where your list came from. If you've imported a large batch from one source, run validation on it before sending.
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