Few enhancements.

modoboa/dmarc/api/v2/viewsets.py

@@ -26,6 +26,8 @@ class DMARCViewSet(GetThrottleViewsetMixin, viewsets.GenericViewSet):
     )
     def alignment_stats(self, request, **kwargs):
         domain = self.get_object()
+        if not domain.record_set.exists():
+            return response.Response(status=204)
         try:
             stats = lib.get_aligment_stats(
                 domain, self.request.query_params.get("period")

modoboa/dmarc/lib.py

@@ -263,8 +263,8 @@ def get_aligment_stats(domain, period=None) -> dict:
            report__end_date__lte=daterange[1])) &
         Q(header_from=domain)
     )
-    all_records = models.Record.objects.select_related().filter(qargs)
-    stats = {
+    all_records = models.Record.objects.filter(qargs)
+    stats: dict = {
         "aligned": {},
         "trusted": {},
         "forwarded": {},