mail.gw vs mail.tm

mail.gw is a temporary/disposable email API that issues throwaway inboxes for testing signups and email-verification flows. Its Hydra/JSON-LD REST API is rooted at api.mail.gw, exposing /domains (available disposable-email domains) and /messages collections, with no API key required for the base entrypoint.

mail.tm issues disposable inboxes on shared domains and exposes a Hydra/JSON-LD REST API to create accounts, fetch a bearer token, and read incoming messages, all without any signup fee. It's the fully free, actively maintained sibling of mail.gw.