Not quite 100% mail order as you have to buy the mailers from the shop, but I have just started using Jessops process paid mailers. I have only sent them two films, but have been very happy with the quality of the work. The biggest problem that I had with them was persuading the Croydon store last year that they were doing mailers again. The conversation went something like "Haven't done them for ages"...... "Your web site says you have them in stock"........ "The lab has closed. Aah here they are, it is a different lab address"