Xu Guoshi, a postman, opens a mailbox located near Xinzhou Road South at around 9 a.m. March 23. There was only one letter in the mailbox. Xu, who has been a postman for nearly 20 years, said that there are now 800 mailboxes in Shenzhen and each mailbox is opened once every day, regardless of the weather. Fewer people write letters these days, since emails, text messages and WeChat are more convenient in the Internet era. SD-Agencies