Goeland is a self-hosted RSS/Atom feed to email digest tool written in Go. It fetches feeds from RSS/Atom/JSON sources, Imgur tags, and Miniflux instances, applies a composable chain of filters (e.g., unseen, today, digest, language, retrieve, replace), and sends beautiful responsive HTML emails via SMTP or writes to HTML files. It runs as a one-shot CLI command or as a persistent daemon with per-pipe cron scheduling. The architecture is modular: commands are defined with Cobra, configuration is read via Viper (TOML files with env overrides), logging uses Logrus with structured output support, and unseen entry tracking uses BoltDB. External dependencies include an SMTP server, Miniflux REST API, Imgur API, and optional CSS themes. The codebase demonstrates strong engineering practices: clean package boundaries, thorough unit tests (filter_test.go covers all filters including edge cases), security-conscious HTTP fetching with SSRF protection, internationalization support, and automated CI/CD with Docker multi-arch builds. It is production-stable and actively maintained.