jcoffey-dev
4b585905d7
While the switch is off, the answers that tell a mail app where to connect stop offering what the switch closed, so a new phone or desktop app is not sent to a port that is shut or a sign-in that will be refused: - Thunderbird-style autoconfig (/mail/config-v1.1.xml and its other paths) and Outlook autodiscover leave out IMAP, POP3 and SMTP submission. - PACC (/.well-known/user-agent-configuration.json) offers JMAP, CalDAV, CardDAV and WebDAV, and no IMAP, POP3, SMTP or ManageSieve. The document is rendered once per configuration load, so the JMAP-only version is rendered beside it and chosen per request; the _ua-auto-config digest in the suggested zone follows, since it hashes the same document. - The suggested zone publishes _imap, _imaps, _pop3, _pop3s, _submission and _submissions with target "." -- "not offered", RFC 6186 section 3.4 -- the spec's decision, rather than dropping them: a client that looks is told, and an automatically managed zone replaces the old records instead of leaving them behind. - It also drops the TLSA records for ports 993 and 995. A TLS pin for a port the switch has closed advertises a service that is not there. Submission's 465 keeps its record: the SMTP lock keeps that port open. The switch is read per answer, as sign-in reads it, so every node agrees the moment it turns. Inbound mail, MX records and the JMAP, CalDAV and CardDAV answers are untouched. tests/e2e/legacy_protocols.py checks all four on a running server: with the switch on they offer IMAP, POP3 and SMTP (the control); while it is off they offer none of them and every legacy SRV name has target "."; and once it is back on, autoconfig and the zone read as they did before. All checks pass.
A complete mail and collaboration server, every feature included, under the AGPL
INBUXA is a mail and collaboration server: JMAP, IMAP, POP3, SMTP, CalDAV, CardDAV and WebDAV, in one Rust binary, with ihasmail as its web front end. It is a fork of Stalwart. Project site: inbuxa.org. Documentation: docs.inbuxa.org.
Stalwart ships some features only in a paid Enterprise Edition: multi-tenancy, masked email, undelete and others. INBUXA ships everything to everybody under the AGPL-3.0, rebuilding those features independently and without using any of Stalwart's Enterprise code.
What's different from Stalwart
- Every feature, one edition. No license key, no edition checks, no
upsell. See
docs/spec/SPEC.md§4 for the features being rebuilt, anddocs/spec/features/for each one's specification. - Webmail and administration by ihasmail, as a separate service that can run beside the server or elsewhere. Stalwart's own web interface is removed, so there's no web front end on the mail host.
- Clean-room rebuilds. Enterprise-only code is stripped from every
upstream release before it's imported. The rebuilt features are written
from specifications that use only public sources (
docs/spec/SPEC.md§3).
How the fork is kept
Upstream releases arrive as stripped snapshots, never with upstream's git
history, which contains Enterprise code. tools/fork/strip.py builds each
snapshot on top of upstream's own ossify.py, then verifies it independently.
The report for every import is in docs/fork/strip-reports/. See
docs/spec/SPEC.md §2.
Building
cargo build --release -p inbuxa # the binary is target/release/inbuxa
docker build -t inbuxa . # or the container image
Settings are read from INBUXA_* environment variables. An existing Stalwart
install's STALWART_* variables still work, with a warning to rename them.
New installs keep their data in /var/lib/inbuxa and logs in
/var/log/inbuxa. Existing installs keep the paths their configuration
already names, so none of their data moves.
License and credits
INBUXA is free software under the GNU Affero General Public License, version 3.
It is a fork of Stalwart, copyright © Stalwart Labs LLC, modified by Coffey Labs in 2026. Upstream's copyright notices are kept on every file they cover, and every upstream file this fork changed says so in its header, under the notice it came with. Stalwart's files are dual-licensed AGPL-3.0-only or Stalwart's Enterprise License, and INBUXA takes them under the AGPL-3.0 only. A few of those files also carry code from other projects under MIT or BSD licenses, which stays under those licenses; THIRD-PARTY.md lists it with its notices. "Stalwart" is Stalwart Labs' name. INBUXA isn't affiliated with or endorsed by Stalwart Labs.
The INBUXA mark reuses ihasmail's cat-and-envelope artwork.