mail order
noun [ U ] uk/ˈmeɪl ˌɔː.dər/ us/ˈmeɪl ˌɔːr.dɚ/
邮购
a way of buying goods in which you choose what you want, usually from a catalogue, and it is sent to you
I often buy clothes by mail order. 我常邮购服装。
a mail-order catalogue/company 邮购目录／公司