Order confirmation emails are not sent for standing order orders.

app/models/spree/order_decorator.rb

@@ -293,7 +293,9 @@ Spree::Order.class_eval do
   # Overrride of Spree method, that allows us to send separate confirmation emails to user and shop owners
   # And separately, to skip sending confirmation email completely for user invoice orders
   def deliver_order_confirmation_email
-    Delayed::Job.enqueue ConfirmOrderJob.new(id) unless account_invoice?
+    unless account_invoice? || standing_order.present?
+      Delayed::Job.enqueue ConfirmOrderJob.new(id)
+    end
   end
 
   def changes_allowed?

spec/models/spree/order_spec.rb

@@ -572,6 +572,14 @@ describe Spree::Order do
         order.deliver_order_confirmation_email
       end.to_not enqueue_job ConfirmOrderJob
     end
+
+    it "does not send confirmation emails when the order belongs to a standing order" do
+      create(:standing_order_with_items, orders: [order])
+
+      expect do
+        order.deliver_order_confirmation_email
+      end.to_not enqueue_job ConfirmOrderJob
+    end
   end
 
   describe "associating a customer" do