YSK always put the word "attached" in an email when you are going to put an attachment because if you forget to put an attachment, most email applications will remind you to attach it.
from /r/YouShouldKnow
YSK在准备放附件的时候,总是在邮件中写上 "附件 "二字,因为如果你忘记放附件,大多数电子邮件应用程序会提醒你放附件。