SMTP Test Tool

The tool validates an SMTP server by performing a controlled session against a specified host and port to confirm reachability, authentication viability, and proper handling of the SMTP command sequence.
It conceptually mirrors a real mail transfer: a client connects, negotiates security as configured, authenticates, and issues MAIL FROM, RCPT TO, and DATA. The system records server banners, per-command responses, and overall success or failure, providing actionable diagnostics without dispatching marketing content.
Developers, system admins, and email engineers gain visibility into handshake behavior, TLS requirements, and error codes. The tool supports both basic test runs and advanced modes that expose raw SMTP transcripts, timing data, and message-id results for integration into CI pipelines or incident investigations. Its value lies in isolating configuration gaps, such as missing STARTTLS, weak ciphers, or incorrect credentials, before going live with campaigns or transactional mail.
Core features include host/port input, credentials, security mode, envelope details, subject and body fields, and an exportable delivery report. Use cases include server validation after DNS or network changes, post-migration checks, and onboarding of new mail servers for developers who need deterministic feedback on mail flow.