BadSMTP

Explore this developer service’s ongoing no-cost allowance, restrictions and official documentation before deploying.

INCLUDED FREE ALLOWANCEGPL-3.0 self-hosted SMTP test server with configurable SMTP error responses, TLS/authentication simulations, message inspection and optional local storage; no vendor-imposed usage quota or expiry for the software.

View official documentation

Plan details

What do these plan and deployment labels mean?

Plan: Ongoing free allowance
Deployment model: Self-hosted
Credit card: Not required
Commercial use: Allowed
Added to directory (UTC): 2026-11-05
Last checked: 2026-11-05

Important restrictions

Testing only: does not relay mail to real recipients. Bring your own host/CI resources and storage; GPL-3.0 obligations apply to redistribution. No free hosted SMTP delivery or infrastructure is included.

View official documentation

Independent community listing, not affiliated with the provider. Always check the latest billing policy and quotas before enabling paid usage.