Launching RustMailer – My Journey to a Fast, Self-Hosted Email API in Rust

Hey Indie Hackers!

After spending years building email middleware at a top internet company, I got fed up with the complexity and frustrations of JVM languages—constant tuning, garbage collection pauses, and random crashes. So, I decided to switch gears and build something better.

That’s how RustMailer was born — a lightweight, reliable, self-hosted email API server written in Rust. It’s the product of my experience and the frustrations I wanted to leave behind.

RustMailer supports IMAP sync, SMTP send, webhooks, REST & gRPC APIs — all packed into a single binary with zero external dependencies. My goal? To create a small but powerful tool that developers can truly own and trust.

This project is still early, and while it’s not free, I welcome anyone to try it out. I’m actively evolving it based on user feedback.

Honestly, I’m currently working on this part-time and hope to earn some living income from it. If enough people find it useful and want to support it, I’d consider going full-time.

Hi, I’m RustMailer, currently living in Fukuoka, Japan — excited to connect with this community and hear your thoughts!

The project is live on GitHub:
👉 https://github.com/rustmailer/rustmailer

Thanks for reading and being part of this journey! 🙌