Spam trap
An address used to detect poor list acquisition or hygiene.
Spam traps are addresses monitored by anti-abuse organizations or mailbox providers. They may be pristine addresses that were never opted in, or recycled addresses that used to belong to real people. Hitting traps is a strong signal of purchased, scraped, or stale lists.
reading this as developers picking email infrastructure
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
Applied to spam trap, that means weighing developer experience, SDK breadth, idempotency keys, and operating track record ahead of the rest, against password resets, receipts, and magic links shipped from application code.