What are some popular self-hosted MTAs?

Self-hosted Mail Transfer Agents (MTAs) give you complete control over your email infrastructure. The most common options:

Postfix: The most widely deployed open-source MTA. Known for security, reliability, and extensive documentation. Default on many Linux distributions. Configuration uses simple text files. Excellent choice for most self-hosted setups.

Exim: Flexible and powerful, popular on cPanel/WHM hosting environments. More complex configuration but highly customizable routing and filtering rules.

PowerMTA: Commercial MTA designed for high-volume sending. Advanced features like automatic IP warmup, bounce processing, and detailed analytics. Used by large senders and ESPs. Requires licensing.

Haraka: Modern MTA written in Node.js. Plugin architecture makes it extensible. Good for developers who want to customize behavior programmatically.

Postal: Open-source mail delivery platform with a web UI. Combines MTA functionality with tracking, webhooks, and multi-organization support.

Self-hosting means self-responsibility. You manage IP reputation, security patches, and deliverability monitoring that commercial services handle for you.