Stalwart Community, free under AGPL-3.0.
Stalwart's Community Edition is free under AGPL-3.0.
Your data, on your infrastructure.
Running your own mail server means your messages live on hardware you control, under policies you set, with no third party indexing the contents for ads or training data. Stalwart gives you the full server to run anywhere you can run a Linux host, with the same flexibility you would get from a hosted provider and none of the lock-in.
- Full ownership of mailboxes, calendars, contacts and files.
- No vendor lock-in; standard protocols on every interface.
- Customise, extend or audit the source to your own standards.
Auditable code, reviewed by the community.
Open source means anyone can read the code, file an issue or contribute a fix. Stalwart is written in Rust, which removes whole categories of vulnerability common in older mail servers (use-after-free, buffer overruns, type confusion in protocol parsers) at compile time. The codebase has been through an independent security audit and the public report is on the blog.
Free software, designed to be deployed.
Stalwart is dual-licensed under the GNU Affero General Public License v3.0 and the Stalwart Enterprise License v1. The AGPL-3.0 obligations apply only when modified versions of the server are themselves redistributed or offered as a network service; running unmodified Stalwart, or using it internally, does not trigger any source-disclosure requirement. Operators that prefer not to comply with AGPL-3.0 on their own modifications can purchase the proprietary SELv1 license through the Enterprise Edition.
Free support from the community.
Community users get a free account on the support portal at support.stalw.art, where questions and bug reports are answered by the wider Stalwart community. For real-time discussion, the project also has active Reddit, Discord and Matrix communities that operators and contributors use day to day.
Built with public-interest funding.
Part of Stalwart's development has been funded by NLnet through two grants. NGI0 Entrust Fund was established by NLnet with financial support from the European Commission's Next Generation Internet programme, under DG Communications Networks, Content and Technology, grant agreement No 101069594. NGI Zero Core was established by NLnet with financial support from the European Commission's programme, under the same DG, grant agreement No 101092990. Public funding has helped Stalwart ship features that benefit the whole open-source ecosystem and stay free for self-hosters.