Skip to content
Get Stalwart

Stalwart Blog

Stalwart v1.0: The Fastest Mail Server on the Planet

- 16 min read
Mauro D.
Mauro D.
Project Maintainer

Five years ago, on 3 October 2021, the first commit landed in a small repository called mail-parser. That e-mail parsing library became the seed of a complete mail and collaboration server, and today, after five years of continuous development, we are proud to announce Stalwart v1.0, the first stable release.

Version 1.0 is about two things: speed and stability. We spent months profiling, benchmarking and rewriting the hot paths of the server, and the result is a mail server that outperforms the Postfix and Dovecot combination in 35 of 38 head-to-head benchmarks. We also finalised the database schema, so future releases will no longer require disruptive migrations.

Private Tests, Public Code: Protecting Stalwart from AI Clones

- 18 min read
Mauro D.
Mauro D.
Project Maintainer

Open source works because it is a relationship that benefits both sides. Lately, a few actors have started treating Stalwart as something to feed on instead. This post explains what has been happening, why our test suites are moving to a private repository, why the license is not changing, and how the Enterprise edition keeps the Community edition alive.

Introducing Sievepad: write and debug Sieve scripts in the browser

- 9 min read
Mauro D.
Mauro D.
Project Maintainer

Sieve has no statement for printing a value or writing to a log, so debugging a mail filter has long meant sending test messages and reading debug headers out of their raw source. Sievepad runs the Stalwart Sieve interpreter in the browser, inside the editor that powers Visual Studio Code, so a script can be written, run and debugged against test messages in seconds, without a server and without sending a single email.

How we use AI at Stalwart

- 10 min read
Mauro D.
Mauro D.
Project Maintainer

AI has become part of how most software gets written, and Stalwart is no exception. But “we use AI” has become such a vague statement that it says almost nothing. So this post is the specific version: where AI measurably helps us, where we deliberately keep it out of the codebase, and why a server designed to run in large clusters still gets its architecture written by hand.

DKIM2 and DMARCbis have landed, and Stalwart speaks them first

- 27 min read
Mauro D.
Mauro D.
Project Maintainer

Email authentication just took its biggest step in a decade. DKIM2 rebuilds DKIM around a verifiable chain of custody that survives forwarding, stops replay, and makes bounces provable, while DMARCbis trades the Public Suffix List for a live DNS tree walk and writes a decade of operational lessons back into the spec. Both are now fully implemented in Stalwart v0.16.12, the first mail server to support them, and both can be tested straight from the browser at the mail-auth playground.