jcoffey-dev
a24ed3b60a
Deliverability spec (inbuxa-drafts specs/deliverability.md), the server side. Every node that sends mail checks itself once a day, at its own minute in the first hour (UTC), and when an administrator asks: - its outgoing addresses (the connection strategy's, or what its EHLO name resolves to), their reverse DNS and whether it resolves back, and nine blocklists, read by each list's own codes so a refused query is never taken for a listing (DL-1 to DL-6); - for every domain: SPF for each address, each DKIM key (by signing a message that's never sent and verifying it as a receiver would), DMARC, the MTA-STS policy against the MX, TLS reporting, and the domain blocklists (DL-7 to DL-12); - whether it holds a certificate for its EHLO and MX names (DL-13). It keeps one report per node, facts only; the console grades them. - inbuxa:DeliverabilityReport: /get, and a create that asks every node to check now, broadcast as DeliverabilityCheck (DL-15). A tenant administrator gets their own domains only (DL-20). - inbuxa:DeliverabilitySettings: which built-in lists are left out, and the lists themselves (DL-6). - sysDeliverabilityGet, sysDeliverabilityUpdate, sysDeliverabilityCheck; a tenant ceiling always turns the last two off.
A complete mail and collaboration server, every feature included, under the AGPL
Note
Development happens on git.coffeylabs.org/inbuxa/inbuxa-server; the copy on GitHub is a read-only mirror. Report issues at git.coffeylabs.org/inbuxa/inbuxa-server/issues, and join discussions at community.coffeylabs.org.
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.