mailer
noun /ˈmeɪlə(r)/
/ˈmeɪlər/
- (especially North American English) (also mailing British and North American English)a letter or package that is sent by mail, especially one that is sent to a large number of people
邮件(尤指成批寄发的) - (North American English) an envelope, box, etc. for sending small things by mail
邮件封套(或小箱、盒等)