Dovel

Dovel is a lightweight SMTP server written in Go that focuses on simplicity and extensibility. It receives and sends email according to a single JSON configuration file and delegates mailbox/storage actions to user-provided hooks. (pkg.go.dev)

Key Features

• Written in Go with a single config file (defaults to $XDG_CONFIG_DIR/dovel/config.json) for easy setup and portability.
• Receives mail and executes executable hooks named receive-<DOMAIN>, passing the message in mbox format to the hook for custom storage or processing.
• Sends mail using a configured vault/users JSON file and supports per-user DKIM signing for outbound messages.
• TLS support via certificate and private key fields in the config (used for encrypted SMTP on submission ports).
• Listens on standard SMTP ports (25, 587, 465, 2525 configurable) and exposes a simple optional web interface for browsing messages.
• Debug/logging controlled by the DEBUG environment variable for developer troubleshooting. (pkg.go.dev)

Use Cases

• Self-hosted personal or small-team mail handling where incoming messages are processed by custom scripts (hooks) and stored in custom formats.
• Developer workflows that need programmatic delivery of inbound email to local tools, APIs, or archiving scripts.
• Simple transactional mail sender for services that can provide per-user DKIM keys and manage DNS records for deliverability. (pkg.go.dev)

Limitations and Considerations

• No built-in IMAP/POP3 mailbox server functionality; message storage/management is delegated to hooks so external tooling is needed for mailbox access.
• No integrated spam filtering, antivirus, or advanced MTA features (bouncing policies, rate limiting, reputational services) — these must be provided externally.
• Deliverability requires correct DNS/SPF/DKIM/DMARC configuration and operational handling (outbound reputation, PTR records) which are not automated by the server. (pkg.go.dev)

Dovel provides a compact, script-extensible SMTP server implementation intended for users who prefer a minimal, Go-based mail gateway that hands message storage and processing to custom hooks. It is most appropriate where straightforward SMTP receive/send behavior and per-message scripting are sufficient.