recorded delivery
noun [ C or U ] UK uk/rɪˌkɔː.dɪd dɪˈlɪv.ər.i/ us/rɪˌkɔː.dɪd dɪˈlɪv.ɚ.i/ (US certified mail)
（信件须由收件人签收确认的）记录式邮递，记录式投递
If a letter is sent by certified mail, the person who receives it must sign their name to show that it has been received.