I make a habit of training the spam filter to catch all the non-important emails produced on a purchase. Tracking link for shipment? Thank you! Random email a

I make a habit of training the spam filter to catch all the non-important emails produced on a purchase. Tracking link for shipment? Thank you! Random email about how to 'best use' my purchase (advertise other products) - instant spam flag. This has worked quite well, though occasionally the filter gets it wrong.