The first of the features held back from the v1.0 cut is here. Stalwart v1.0.2 introduces an encryption gateway that encrypts outgoing mail for its recipients, a new OpenPGP and S/MIME engine with modern and post-quantum algorithms, and a restyled WebUI. Everything in this post is open source.
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.
Today we released Stalwart v0.16.10, a release that closes every single open bug report we have on record: both the legacy issues on GitHub and the reports filed through our new support portal. With the tracker clear of bugs, we want to share where Stalwart stands today and what is left before we ship version 1.0.
After more than three months of focused work, we are thrilled to announce the release of Stalwart v0.16. This is easily the most ambitious release we have ever shipped, with literally hundreds of new features, improvements, and fixes across every corner of the server.
We will be upfront about something: v0.16 will feel like a new product on first contact. Several long-standing concepts have been reworked, a few have been removed, and many new ones have been introduced. This was a deliberate choice. Stalwart has been under continuous development for nearly five years, and both the feature set and the user base have grown far beyond what the original configuration and management layer was designed for. Rather than keep patching around those limits, we took the opportunity to rebuild the foundation. The payoff is a much cleaner architecture and a long list of features that were simply not implementable before, many of which had been sitting on the community wishlist for years.
Let’s walk through the highlights.
