Covertly add to an email

• Send to secretly, in a way
• Secretly include, maybe
• Include secretly, as in an email
• Surreptitiously email
• Discreetly keep in the email loop, for short
• Secretly loop in
• Send covertly, as an email
• Secret attachment, for short
• Include surreptitiously, in a way

Wiktionary Word definitions in Wiktionary
init. 1 body-centered cubic 2 blind carbon copy vb. to send something by blind carbon copy