base-trixie: the image on Debian trixie, Postfix 3.10.13; Received: hidden on 465/587

The runtime base is debian:trixie-slim, the build stage golang:1.26-trixie:
Postfix 3.10.13 with upstream's 2026 security fixes up to the August
batch, libmilter 8.18.1, OpenSSL 3.5. Every citation of another program in
code, scripts and documents was re-read against the trixie sources
(dev/upstream; bookworm's kept in dev/upstream-bookworm) and updated;
development.md's cited-package table holds the trixie versions.

What the re-reading changed in behaviour:
- logtail: reject lines with sasl_method/sasl_username/sasl_sender
  (smtpd_check.c:1019-1026); cleanup's "removed (canceled)" forgets a
  port-25 id (cleanup_api.c:363-364).
- internal/postfix/retry.go reads postconf's stdout only: since 3.9 a
  deprecated-parameter warning on stderr made one value too many and the
  panel fell back to the compiled-in retry policy.
- logrotate-loop.sh: logrotate 3.22 exits 1 when it ignores a config;
  the loop refuses on that output whatever the status.
- postfix-config.sh: cyrus_sasl_config_path set explicitly (bookworm's
  07_sasl_config.diff is gone); maillog_file_permissions=0640; mynetworks
  explicit; Dockerfile: SYNC_CHROOT= in /etc/default/postfix,
  opendkim-tools dropped, openssl named, systemd-standalone-sysusers so
  cron does not bring the whole of systemd.
- The selfpost group is 10998, outside the system range 100-999: in
  trixie a package took 998 and the build failed (owner's decision:
  a conflict-free id, the distribution's own ids untouched). The
  entrypoint hands /data back by name when the user or the group differs.
  Guide, backup refusal text, help (design commit 68ec8b2), e2e.
- smtpd_hide_client_session=yes on smtps and submission (owner's
  decision): Received: names no client, TLS, login or protocol; port 25
  keeps the full header. e2e checks both.
- test/upstream/opendkim-probe.sh makes keys with openssl genrsa.

Tests: on the server, make e2e exit 0 (674 s, the image built on trixie),
go vet + go test 27 packages ok. CHANGELOG [Unreleased], guide,
architecture.md, security.md, roadmap.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/postfix/retry_test.go

@@ -2,12 +2,15 @@ package postfix
 
 import (
 	"errors"
+	"fmt"
+	"os"
+	"os/exec"
 	"testing"
 	"time"
 )
 
 // The postconf values in these tests are composed by hand: values main.cf
-// could hold. Stock Postfix 3.7.11 prints "0h" for delay_warning_time
+// could hold. Stock Postfix 3.10.13 prints "0h" for delay_warning_time
 // (src/global/mail_params.h, DEF_DELAY_WARN_TIME), not "0".
 func TestLoadRetryPolicyUsesPostconfValues(t *testing.T) {
 	old := readRetryConf
@@ -29,7 +32,7 @@ func TestLoadRetryPolicyUsesPostconfValues(t *testing.T) {
 	if p.MaximalQueueLifetime != 2*24*time.Hour {
 		t.Errorf("MaximalQueueLifetime = %v, want 2d", p.MaximalQueueLifetime)
 	}
-	// 5d over a maximal 2d: qmgr uses 2d (Postfix 3.7.11, src/qmgr/qmgr.c,
+	// 5d over a maximal 2d: qmgr uses 2d (Postfix 3.10.13, src/qmgr/qmgr.c,
 	// qmgr_post_init(), "adjusting bounce_queue_lifetime").
 	if p.BounceQueueLifetime != 2*24*time.Hour {
 		t.Errorf("BounceQueueLifetime = %v, want 2d", p.BounceQueueLifetime)
@@ -40,7 +43,7 @@ func TestLoadRetryPolicyUsesPostconfValues(t *testing.T) {
 }
 
 // A message lives at most maximal_queue_lifetime: qmgr caps
-// bounce_queue_lifetime at it (Postfix 3.7.11, src/qmgr/qmgr.c,
+// bounce_queue_lifetime at it (Postfix 3.10.13, src/qmgr/qmgr.c,
 // qmgr_post_init()), so a larger bounce lifetime does not lengthen it.
 func TestLongestLifetimeIsTheQueueLifetime(t *testing.T) {
 	p, err := parseRetryPolicy([]string{"300s", "300s", "4000s", "1d", "5d", "0h"})
@@ -95,3 +98,41 @@ func TestParseRetryPolicyStock(t *testing.T) {
 		t.Errorf("parsed = %+v", p)
 	}
 }
+
+// TestFakePostconf is not a test: it is the fake `postconf -h -x` the test
+// below runs in place of the real one. Its warning is composed after Postfix
+// 3.10.13, src/postconf/postconf_unused.c, pcf_flag_unused_parameters(),
+// written to stderr after the values (src/postconf/postconf.c, main()).
+func TestFakePostconf(t *testing.T) {
+	if os.Getenv("SP_FAKE_POSTCONF") != "1" {
+		t.Skip("helper process")
+	}
+	fmt.Fprint(os.Stdout, "300s\n300s\n4000s\n2d\n5d\n0h\n")
+	fmt.Fprint(os.Stderr, "postconf: warning: /etc/postfix/main.cf: support for parameter \"smtpd_use_tls\" will be removed; instead, specify \"smtpd_tls_security_level\"\n")
+	os.Exit(0)
+}
+
+// postconf's warnings are not values: since Postfix 3.9 a deprecated
+// main.cf parameter draws one on every run, and read with the values it made
+// one line too many, so the panel showed the compiled-in defaults.
+func TestPostconfRetryValuesReadsStdoutOnly(t *testing.T) {
+	old := postconfRetryCmd
+	postconfRetryCmd = func() *exec.Cmd {
+		cmd := exec.Command(os.Args[0], "-test.run=^TestFakePostconf$")
+		cmd.Env = append(os.Environ(), "SP_FAKE_POSTCONF=1")
+		return cmd
+	}
+	t.Cleanup(func() { postconfRetryCmd = old })
+
+	lines, err := postconfRetryValues()
+	if err != nil {
+		t.Fatalf("postconfRetryValues: %v", err)
+	}
+	p, err := parseRetryPolicy(lines)
+	if err != nil {
+		t.Fatalf("parse %q: %v", lines, err)
+	}
+	if p.MaximalQueueLifetime != 2*24*time.Hour || p.FromDefaults {
+		t.Errorf("policy = %+v, want the postconf values", p)
+	}
+}