Everyone likes a good Dumbass Thief story, and the Post provides a very good one today. Sayaka Fukuda got her purse jacked on the Fifth Avenue N platform in February. Later she noticed a picture in her email outbox that she knew she hadn’t sent. Turned out the thief had taken his own photo with the stolen cellphone and emailed it to himself (above). The victim notified the cops and also notified the thief, whose address was now available to her. The thief threatened to kill her, which seems a poor course of action for someone on the verge of arrest. When inevitably apprehended, 18-year-old Daquan Mathis confessed to the crime and to a separate armed robbery, and is probably thinking that when he breaks out of prison, he will send his stolen cellphone photos to a magical email address that no one can trace, and then star in a dance video. May all our mugs, punks, and skels be equally inept.