jcoffey-dev
e0060c9e6e
Phase 2f of the DLP and mail flow rules spec: the rules now run on mail
an authenticated sender submits, after the DATA system script and
before headers and DKIM signing (§2.1).
- smtp/inbound/mailflow.rs: builds what the rules look at from the
message (subject, the text version of each body, one level of attached
messages, attachment text via the extractor, 10 MB of text at most)
and the envelope (sender's groups and tenant; each recipient local or
not, and its groups). Skipped entirely when no enabled rule applies to
outgoing mail. Rules that can't be loaded refuse with a 451: nothing
unchecked leaves.
- Block: 550 5.7.1 with the rule's notice. Warn: 550 5.7.1 with the
notice and how to override: "[override: reason]" at the start of the
subject, taken out before the message goes on (settled answer 1).
Until phase 3, a hold rule blocks rather than let mail through.
- JMAP: EmailSubmission takes inbuxa:dlpOverride {reason}; a refusal
comes back as inbuxa:dlpWarning or inbuxa:dlpBlocked with each rule's
name and notice (description too, for older clients).
- Audit: one record per DLP match, the sender as actor, action create,
target a message: the recipient domains, each rule with its detectors'
counts, the outcome, an override's reason. Never the matched text. No
new audit action: an older node that meets one fails its daily
clean-up, which would make rolling back unsafe (spec §2.7 updated).
Tests: mail_rules_tests gains the DLP flow over JMAP (no rules, warning
with rule and notice, local recipient not warned, override with a
reason, block that no reason passes, the subject tag stripped from the
delivered message, audit records with no card or key text). smtp
inbound tests pass; system_tests passed twice after one timeout in the
email delivery tests that didn't recur.
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.