Rspamd
Rspamd is an open-source, high-performance spam filtering system designed to process and classify email messages. It uses a combination of rule-based filtering, statistical analysis (Bayesian filtering), and machine learning techniques to detect spam, phishing, and malware. The system is modular, scalable, and integrates with various mail transfer agents (MTAs) like Postfix, Exim, and Sendmail.
Developers should learn and use Rspamd when building or maintaining email infrastructure that requires robust spam and malware protection, such as for email servers, hosting providers, or enterprise email systems. It is particularly valuable for its performance in high-volume environments, real-time processing capabilities, and extensive configurability through Lua scripts and plugins.