Deliverability & the inbox
Spam trap
Also known as: honeypot email
An email address mailbox providers and deliverability services create specifically to catch senders with poor list hygiene — sending to one damages reputation immediately, sending to many can get a domain blacklisted.
Spam traps are email addresses created specifically to catch senders who don't maintain clean lists. Three types: pristine traps (addresses that never belonged to a human — scraped or guessed list gives them away), recycled traps (addresses that were real accounts but got abandoned and re-purposed as traps after ~12 months of inactivity), and typo traps (gmial.com, yahooo.com — scraped from bad sign-up forms). Hitting one spam trap isn't fatal but signals to mailbox providers that your list hygiene is poor. Hitting many — or hitting the same trap twice — triggers blocklist entries at Spamhaus and other RBLs, which can shut down deliverability across mailbox providers for weeks. Prevention: double opt-in on new subscribers, sunset sequences for 12+ month dormant users, real-time email-verification on signup forms.