added JMAP (not tested yet)

internal/relay/queue_test.go

@@ -1,11 +1,15 @@
 package relay
 
 import (
+	"io"
 	"net"
 	"os"
+	"strconv"
 	"testing"
 	"time"
 
+	"github.com/emersion/go-smtp"
+
 	"mailgoserver/internal/db"
 	"mailgoserver/internal/toolbox"
 )
@@ -190,3 +194,78 @@ func TestProcessQueueOnceExhaustsRetriesAndBounces(t *testing.T) {
 		t.Errorf("expected email_log status 'failed', got %q", log.Status)
 	}
 }
+
+// rejectingBackend is a stand-in "receiving MTA" that rejects every RCPT with a fixed
+// SMTP status/message — used to prove a permanent (5xx) rejection bounces on the first
+// attempt instead of working through retrySchedule.
+type rejectingBackend struct{ code int }
+
+func (b *rejectingBackend) NewSession(*smtp.Conn) (smtp.Session, error) {
+	return &rejectingSession{code: b.code}, nil
+}
+
+type rejectingSession struct{ code int }
+
+func (s *rejectingSession) Mail(from string, opts *smtp.MailOptions) error { return nil }
+func (s *rejectingSession) Rcpt(to string, opts *smtp.RcptOptions) error {
+	return &smtp.SMTPError{Code: s.code, EnhancedCode: smtp.NoEnhancedCode, Message: "poor reputation"}
+}
+func (s *rejectingSession) Data(r io.Reader) error { _, err := io.ReadAll(r); return err }
+func (s *rejectingSession) Reset()                 {}
+func (s *rejectingSession) Logout() error          { return nil }
+
+func TestProcessQueueOnceBouncesImmediatelyOnPermanentRejection(t *testing.T) {
+	database := testDB(t)
+	s := smtp.NewServer(&rejectingBackend{code: 554})
+	s.Domain = "mx.example.com"
+	s.AllowInsecureAuth = true
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { s.Close() })
+	go s.Serve(l)
+	_, portStr, _ := net.SplitHostPort(l.Addr().String())
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	r := &Relay{
+		DB: database, Hostname: "sender.example.com", Timeout: 5 * time.Second,
+		Logger: toolbox.GetLogger("relay_test"), port: port, mxLookup: fixedMXLookup,
+	}
+
+	logID, err := database.InsertEmailLog(db.EmailLog{MailFrom: "from@example.com", ToAddress: "to@dest.example", Status: "queued"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := database.InsertEmailRecipientLog(db.EmailRecipientLog{EmailLogID: logID, Recipient: "to@dest.example", RecipientType: "to", Status: "queued"}); err != nil {
+		t.Fatal(err)
+	}
+	if err := r.EnqueueForDelivery(logID, "from@example.com", []string{"to@dest.example"}, []string{"to"}, "Subject: hi\r\n\r\nbody"); err != nil {
+		t.Fatal(err)
+	}
+
+	// One tick. If this were misclassified as a transient failure it would still be
+	// pending (rescheduled per retrySchedule), not gone.
+	r.ProcessQueueOnce(5, 10)
+
+	pending, err := database.CountPendingRelayQueueItemsForEmailLog(logID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if pending != 0 {
+		t.Fatalf("expected the queue row to be gone after a single permanent (5xx) rejection, got %d pending", pending)
+	}
+	recipients, err := database.ListRecipientLogsForEmail(logID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if recipients[0].Status != "failed" {
+		t.Errorf("expected recipient status 'failed' immediately on a 554, got %q", recipients[0].Status)
+	}
+	if recipients[0].ErrorMessage == "" {
+		t.Error("expected the recipient log to carry the server's rejection reason")
+	}
+}