Remove restrictions that prevent mails to be sent to addon-product-attendees

src/pretix/plugins/sendmail/forms.py

@@ -158,7 +158,12 @@ class OrderMailForm(BaseMailForm):
         ),
         label=pgettext_lazy('sendmail_form', 'Restrict to products'),
         required=True,
-        queryset=Item.objects.none()
+        queryset=Item.objects.none(),
+        help_text=pgettext_lazy(
+            'sendmail_form',
+            'There may be multiple mails sent out to the same mail address if one order contains multiple attendee '
+            'products for it, if you restrict to products while also restricting mails to attendees only. '
+            'This is intended, as every one of those get linked to their own separate order page restricted to only that product.')
     )
     filter_checkins = forms.BooleanField(
         label=_('Filter check-in status'),
@@ -366,6 +371,11 @@ class RuleForm(FormPlaceholderMixin, I18nModelForm):
             del self.fields['subevent']
 
         self.fields['limit_products'].queryset = Item.objects.filter(event=self.event)
+        self.fields['limit_products'].help_text = pgettext_lazy(
+            'sendmail_form',
+            'There may be multiple mails sent out to the same mail address if one order contains multiple attendee '
+            'products for it, if you restrict to products while also restricting mails to attendees only. '
+            'This is intended, as every one of those get linked to their own separate order page restricted to only that product.')
 
         self.fields['schedule_type'] = forms.ChoiceField(
             label=_('Type of schedule time'),

src/pretix/plugins/sendmail/tasks.py

@@ -85,8 +85,6 @@ def send_mails_to_orders(event: Event, user: int, subject: dict, message: dict,
                     )
                 ),
             ).prefetch_related('addons', 'subevent'):
-                if p.addon_to_id is not None:
-                    continue
 
                 if p.item_id not in items and not any(a.item_id in items for a in p.addons.all()):
                     continue
@@ -106,6 +104,10 @@ def send_mails_to_orders(event: Event, user: int, subject: dict, message: dict,
 
                 if p.attendee_email == o.email and send_to_order:
                     continue
+                # the amount of mails could be further restricted if we filter out those where the addon-attendee-email
+                # is the same as the main-product-attendee-email, however, that bears many issues, e.g. if one of
+                # those mail-addresses was only a placeholder or if restrictions are set and the main-product is
+                # excluded -- for now it seems best not to filter them at this point in time
 
                 if subevent and p.subevent_id != subevent:
                     continue

src/pretix/presale/views/order.py

@@ -174,7 +174,6 @@ class OrderPositionDetailMixin(NoSearchIndexViewMixin):
     def position(self):
         qs = OrderPosition.objects.filter(
             order__event=self.request.event,
-            addon_to__isnull=True,
             order__code=self.kwargs['order'],
             positionid=self.kwargs['position']
         ).select_related('order', 'order__event')