A message's From: line is held against the application that sends it, under
the rule Postfix holds the envelope sender to. OpenDKIM chooses the key by
that line, so until now an application could have mail signed as another
domain of the server or as the server itself.
The check (internal/milter/sender.go)
- A role of the panel on a socket of its own (SENDER_CHECK_SOCKET), first in
smtpd_milters and strict: default_action=tempfail. The journal milter keeps
its socket and stays fail-open. postfix-wrapper waits for the new socket.
- It reads no database: what an application may send as comes from Postfix's
own sender_login_maps, what the server signs for from OpenDKIM's
SigningTable. Both are read again when they change; one that cannot be
read defers mail.
- One From: field, one address, allowed by the envelope's lookup; then no
other name of the SigningTable may appear anywhere in the raw line.
Refused: 550 5.7.1 naming the line, reduced to printable ASCII.
- A refusal is a send-log row with reason "from" and the header address
(migration 0006), written by another goroutine and not waited for. The
journal's refusals record their reason too (limit, client), and the
notifier takes only a limit's.
What it costs (docs/plans/from-header-binding.md, Statistics)
- The role marks itself alive every 2 s; at start the gap since the mark is
downtime, counted from Postfix's start if later and not at all when
supervisord says Postfix is not running.
- The log tailer counts the connections Postfix turned away: a warning that
names the socket, then milter-reject "Service unavailable" from the same
smtpd. Seen on the stand: the client is refused from CONNECT on and leaves
at AUTH (454), so no MAIL line is ever written.
- sender_check_days, a row per UTC day, kept a year.
Pages
- Health: the card "Sender check", the socket's row, and the cards layout -
boxes numbered by importance in two stacks read in rows; the left stack
polls, the three readings of the right one are swapped in by id.
- Outbound log: a refused row says why in its tag (wrong From, wrong client,
rate-limited); the message's page shows the From: line and what the
application may send as.
- Help: topic "Sender check", word for word the mockup's.
Found by the stand, fixed here: the names for the second look came from the
sender bindings, and a domain with a key and no application yet was not
among them.
e2e: negative_journal_milter_fail_open is gone - it proved that mail passes
with the panel down, which is no longer so. In its place
sender_check_holds_the_from_line (another domain's From:, the hostname's, a
stranger's, an address off the list, another sender in the display name -
refused; own addresses - delivered) and panel_down_defers_mail (4xx with the
panel stopped, the container alive, mail again after, downtime and one
deferred message on Health, the card warning).
Test server, this tree before the last cosmetic edits (a fixture row, a
fact's size, docs): go vet ok, go test 23 packages ok, make e2e ok (337 s).
Locally after them: internal/web/view ok.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Security fix, outside the inbound antispam feature. Found by its
technical review (Opus, 2026-10-12), reproduced on the test stand
before the fix: over an application's level-2 limit, two MAIL FROM on
one connection were answered 451 and then accepted.
Cause. Postfix introduces a client to a milter once per connection.
The milter library (go-milter 0.4.1, session.go) replaces the milter's
session after any reply that is not "continue" - a refusal, or the
accept that used to end a message. The new session never saw Connect,
so it had no client address, and both checks passed a message without
one: overLimit returned early ("no client IP to key on") and
authIPAllowed did the same. So every message after the first on a
connection, and every MAIL FROM after a refused one, skipped the
level-2 limit and an application's client IP list. In the code since
1.9.0 for the list and longer for the limit.
Fix.
- build/postfix-config.sh: milter_mail_macros carries {client_addr},
so the address comes with every MAIL FROM; MailFrom reads it (both
spellings of IPv6) in the journal milter and the inbound journal
milter.
- overLimit no longer asks for a client address: a ceiling is on a
domain or an application.
- authIPAllowed refuses an application that has a client IP list when
no address is known.
- Body replies "continue" in both milters, which lets the message
through as "accept" did and keeps the session.
The inbound journal milter had the same cause with a smaller effect:
rows of a connection's later messages had no client address.
In the same file, the checks of INBOUND_ANTISPAM_MILTER and
INBOUND_JOURNAL_MILTER_SOCKET refuse any character outside their set
first: a glob's "*" matched anything after the first characters.
Tests: a session that never saw Connect is judged by the macro, a
listed and an unlisted address, no address, not an address; the limit
with no client address; the inbound milter answers only "continue".
test/e2e sends two MAIL FROM on one connection over the limit and
wants both refused.
Checked on the test server: e2e red before the fix on exactly that
check, green after; go vet ./... ok, go test ./... ok (22 packages).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Application sending controls: client IP allow-list for authorization, and level-2 rate limits that override the domain ceiling per application.
Added:
- Per-application **client IP allow-list** on the domain page: when enabled,
- SQLite migration `0009_application_auth_ips.sql` (moves legacy trusted IPs
Changed:
- Application level-2 rate limit **overrides** the domain limit for that login
- Domain export/import carries `auth_ip_restrict` / `auth_allowed_ips`; legacy
- Panel help, Settings, and [guide.md](docs/guide.md) describe override semantics
- [guide.md](docs/guide.md): full-backup section documents all four capture
Full detail: CHANGELOG.md (1.9.0).
[1.0.0]
Added:
- A **Delivery log** on each delivery's page (`/deliveries/{id}`): the
- A **History** block on the same page: the journal's two timestamps stated as
Fixed:
- Postfix config: copy TLS cert/key from the (often `:ro`, host-owned) mount
- Postfix config: allow `maillog_file` under `/data` via
- E2e: read `/data/setup-token` via `docker compose exec` (file is `0600`
- Entrypoint: check `SELFPOST_HOSTNAME` before `/data` setup (so a bad identity
- E2e gate: wait for host-published `/healthz` before panel setup, and stop
… (3 more in CHANGELOG)
Changed:
- Document what `.spbk` and `.spde` stand for (SelfPost backup / SelfPost domain
- Docs aligned with the code: setup URL is `/setup/<token>` (README and
- Full backups no longer carry `/data/log`. It is Postfix's raw log plus its
- Monitoring screens (status, mail queue, system log, deliveries) use adaptive
- Documentation package consolidated into `docs/development.md`: Documentation
… (4 more in CHANGELOG)
[1.0.1]
A documentation and packaging release: no change to the mail path, the database, or the on-disk layout. Upgrading is a tag bump.
Added:
- `SECURITY.md` — how to report a vulnerability privately (GitHub private
- [docs/plans/](docs/plans/) — one document per agreed extension: the optional
Changed:
- The panel's **Account** entry is now called **Settings** — nav link, page
- The signed-in name in the panel's nav is now labelled `User:`, so it reads as
- [docs/product.md](docs/product.md) reframes the future line: the inbound
- [docs/security.md](docs/security.md) is now in English, matching the rest of
- The README documentation table now points at `SECURITY.md` for reporting a
… (2 more in CHANGELOG)
Fixed:
- The panel's static assets are served with a content ETag and
Squashed CHANGELOG sections: [1.0.0], [1.0.1].
Full detail: CHANGELOG.md (1.0.0, 1.0.1).
A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
Added:
- A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
- A **DNS** badge in the domain list, one per row, carrying the same
- Machine metrics on the status page: a **Machine** card reporting the
- An index of the current page's own sections in the navigation column, for the
Changed:
- Every panel page is laid out in one column of the same width, so moving
- The mark's small-size variant — the tab icon and the `SP` initials it
- The stamp's `SELF-HOSTED SMTP RELAY` line is set at 11.5/0.15 instead of
- The delivery log lists what identifies a message and nothing else: time,
- Subjects are decoded for display as well as on the way in, so the rows the
… (4 more in CHANGELOG)
Full detail: CHANGELOG.md (0.6.0).
A bounce could be recorded as a successful delivery. The log-tailer's
Fixed:
- A bounce could be recorded as a successful delivery. The log-tailer's
- Log-tailer resumes where it stopped instead of jumping to end-of-file on
- Level-2 rate limit no longer overshoots under concurrency: messages that
Changed:
- The project has a single public home: `github.com/mixeme/selfpost`. Codeberg
- Code comments no longer cite the archived specification. References like
- `docs/code-review.md` is gone. Its plan is finished — phases 0 (bar the
- `docs/architecture.md` gained a *Code layers* section: a diagram of
- Phase 1 doc/code hygiene (`docs/code-review.md`): removed ~30 stale
… (1 more in CHANGELOG)
Security:
- Pre-release security review (plan § D, model Fable, 2026-08-06): full pass
- `saslpasswd2` argv: the application login is now passed after a `--`
Added:
- Optional password encryption for the two secret-bearing downloads (plan
- Domain import accepts an encrypted export: the envelope is detected by its
- `selfpost-backup` writes encrypted archives and reads them back:
- `TestParseDelivery` covers the exotic mail.log shapes the review asked for
- docs: README *Encrypting a backup or export*; `docs/security.md` §
… (14 more in CHANGELOG)
Removed:
- docs: `security.md` — accepted risk «restore old backup revives session rows»
Changed:
- docs: `implementation-plan.md` trimmed to the sole open v1.x gate — pre-release
- docs: `architecture.md` — sessions (SQLite, idle renew, password change),
- docs: `development.md` — expanded e2e stack and `release.yml` matrix workflow.
- docs: `security.md` — accepted risk for send-log rows stuck at `queued` after
- docs: `roadmap.md` — optional send-log / `mail.log` follow-ups under v1.x tail.
… (10 more in CHANGELOG)
Full detail: CHANGELOG.md (0.5.0).
The project's mark is now in use rather than only on file. The README opens
Added:
- The project's mark is now in use rather than only on file. The README opens
Changed:
- panel: the sign-in and setup pages are now a column the width of their own
- panel: the three monitoring pages — Deliveries, Mail queue, System log — are
Fixed:
- panel: Deliveries now shows the subject as text rather than as its MIME
- panel: table cells may now break inside a word, so no single long value can
- panel: the Applications list on a domain page no longer comes apart. It was a
Full detail: CHANGELOG.md (0.4.0).
Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`).
Added:
- Panel (Go, single static binary) with SQLite persistence, one-time
- Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and
- Application (sender identity) management: SASL credentials via `sasldb2`,
- Full Postfix relay config generated from env at container start: SMTPS 465,
- Journal milter (pure Go, `go-milter`) recording every send to `send_log`;
… (6 more in CHANGELOG)
Full detail: CHANGELOG.md (0.1.0).
mixandClaude Opus 5.5