log tailer: expiry, Postfix's time values and refusal lines as Postfix writes them

Expiry (assumptions A-8). Postfix 3.7.11 logs the end of a message's queue
lifetime once per message, "<id>: from=<..>, status=expired, returned to
sender" (src/qmgr/qmgr_active.c, qmgr_active_done_25_generic()), with no
line per recipient; the tailer waited for "to=..., status=expired", which
no Postfix writes, and the sweep closed only queued rows, so such rows
stayed deferred. The tailer now reads qmgr's line (ExpireMessage: each
recipient's newest open row of the id becomes bounced); the sweep closes a
deferred row too when Postfix no longer holds the message, and counts as
missed only a final line (sent, bounced, expiry). The queue listing's '#'
(forced expiry, showq_compat.c showq_message()) is read as a flag (B-PQ1).

Time values (B-PQ10, B-PQ11): conv_time() ported - one number, one
lower-case unit, the parameter's default unit when none (get_def_time_unit:
d for the lifetimes, h for delay_warning_time), the rest ignored; postconf
-h -x expands $name; bounce_queue_lifetime capped at maximal_queue_lifetime
as qmgr_post_init() caps it, so LongestLifetime is the queue lifetime.

Refusals (A-21, A-23, A-24, A-15): smtpd_whatsup() ends the NOQUEUE line
with sasl_username=<login> on an authenticated session; the line is now
matched to its row by client, login and sender, and a line without a login
is no application's. The client= line's login ends at the comma. The
"IPv6:" trim goes (namaddr is built from state->addr). A row recovered from
cleanup's line says that line names the last recipient only.

Stand (2026-10-14, make e2e, exit 0): new expired_message_is_closed -
defer_transports=smtp makes the retry service defer the message, postsuper
-e and postqueue -i force its expiry; mail.log has "<id>:
from=<alerts@sender.e2e.test>, status=force-expired, returned to sender"
and the row goes deferred -> bounced; refusals_show_postfixs_line passes
with the login match. go vet and go test ./... pass on the server.

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

internal/postfix/retry_test.go

@@ -29,14 +29,29 @@ func TestLoadRetryPolicyUsesPostconfValues(t *testing.T) {
 	if p.MaximalQueueLifetime != 2*24*time.Hour {
 		t.Errorf("MaximalQueueLifetime = %v, want 2d", p.MaximalQueueLifetime)
 	}
-	if p.BounceQueueLifetime != 5*24*time.Hour {
-		t.Errorf("BounceQueueLifetime = %v, want 5d", p.BounceQueueLifetime)
+	// 5d over a maximal 2d: qmgr uses 2d (Postfix 3.7.11, 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)
 	}
 	if p.DelayWarningTime != 0 {
 		t.Errorf("DelayWarningTime = %v, want 0", p.DelayWarningTime)
 	}
 }
 
+// A message lives at most maximal_queue_lifetime: qmgr caps
+// bounce_queue_lifetime at it (Postfix 3.7.11, 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"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p.LongestLifetime() != 24*time.Hour || p.BounceQueueLifetime != 24*time.Hour {
+		t.Fatalf("LongestLifetime %v, BounceQueueLifetime %v; want 24h both", p.LongestLifetime(), p.BounceQueueLifetime)
+	}
+}
+
 func TestLoadRetryPolicyFallsBackWhenPostconfFails(t *testing.T) {
 	old := readRetryConf
 	readRetryConf = func() ([]string, error) {