Anyone could host a copy of a front end on a server of their own, collect a person's password there, and replay it as HTTP Basic against JMAP or the API. Cross-origin rules don't stop that, since a server isn't a browser, and neither does client registration, since Basic never goes through OAuth (contract C-23). JMAP (session, API, upload, download, event source, WebSocket), /api, /auth/introspect, /auth/userinfo and authenticated /auth/register now refuse an Authorization: Basic header before looking at the password, with a 401 whose only challenge is Bearer. A wrong password gets the same answer as the right one. CalDAV and CardDAV keep Basic, and their 401s still offer it. The sign-in page's /api/auth takes the password in its body and is unaffected, as is the token endpoint's client authentication. Bootstrap and recovery mode accept Basic everywhere, as they keep permissive CORS. INBUXA_HTTP_BASIC_AUTH=all puts it back everywhere; dav is the default, and any other value logs a warning and keeps it. Test builds accept Basic everywhere, since the integration suites sign in with passwords, and legacy_protocols.py sets the variable. Tested: unit tests for the paths, and tests/e2e/http_basic_auth.py against the debug build, 26 checks, including both front ends' sign-in path and a refused unregistered redirect for an ordinary account.
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 aren't read: the server stops at startup and
names each one to rename.
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.