Bcc指暗送，即收件人看不到这封邮件还发给了谁，通常用于不想让收件人知道你还发给了谁。
Cc means a ‘carbon copy’ of the email is sent to someone, who is generally boss; Bcc means that a ‘blind carbon copy’ is sent to people whose email addresses will not be seen by the recipient .
秘密抄送
BCC是 “blind carbon copy” 的缩写，表示秘密抄送。
同理可推，CC是 “Carbon Copy” 的缩写，表示抄送。
