Spam Trap
An email address used only to catch senders with poor list hygiene, never legitimately signed up for any mail.
A spam trap is an email address that exists only to receive spam. Pristine traps are never used for any signup, so any mail arriving means the sender scraped or guessed the address. Recycled traps are old abandoned addresses that mailbox providers turn into traps after a long inactivity period, so hitting one means the sender's list is stale. Hitting traps damages sender reputation severely and is one of the fastest paths to a deny-list listing. Good list hygiene (confirmed opt-in, prompt suppression of hard bounces, sunset policies for unengaged recipients) prevents trap hits.