Over the past few months, two different groups have started to treat Stalwart less like a partner and more like a host. […]

The first are forks built with LLMs. We have received reports of projects that take Stalwart, then use AI coding tools to rewrite the features of our Enterprise edition and publish the result under the AGPL […]

The second are cloud providers. We have received emails from companies that run Stalwart as a service and do not like the AGPL’s requirement to share their modifications. The message, worded politely, is that if we do not offer them different terms, they will have Stalwart rewritten under a permissive license such as MIT, so they can keep their changes private and owe nothing to anyone.

Our test suite is where those five years of discoveries live. Every test and every fixture in it encodes something we learned the hard way, often from a bug report sent by one of you. For a human, that suite is documentation. For an AI coding agent, it is something far more valuable: an oracle. An agent with access to the tests does not need to understand why a behaviour is correct.

That is why the Enterprise edition exists, and why we are protecting it. Not to make Stalwart less open, but to make sure there is still a Stalwart around to be open in five years’ time.