Swaks Local SMTP Protocol Tester

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

INCLUDED FREE ALLOWANCEFree GPL-2.0-licensed command-line SMTP/ESMTP/LMTP protocol testing utility with TLS, authentication and scripted message transactions; no vendor-hosted sending quota.

View official documentation

Plan details

What do these plan and deployment labels mean?

Plan: Ongoing free allowance
Deployment model: Local / embedded
Credit card: Not required
Commercial use: Allowed
Added to directory (UTC): 2026-11-08
Last checked: 2026-11-08

Important restrictions

Runs on user-provided systems and requires access to an SMTP server for tests; external SMTP delivery, accounts and infrastructure are not included. Maintained by one developer without guaranteed support.

View official documentation

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