Covertly loop in

• Abbr. atop some e-mails
• Loop in secretly
• Discreetly send a dupe email to
• Include in an e-mail without other recipients knowing
• Secretly include, maybe
• Discreetly keep in the email loop, for short
• Include surreptitiously, in a way
• Letters in front of an e-mail address
• Abbr. in an email field

Wikipedia Word definitions in Wikipedia
BCC may refer to: