Cc
Carbon copy: the header field listing secondary recipients who receive a copy of the message, visible to everyone who gets it.
What it means
RFC 5322 describes the Cc field as the addresses of others who are to receive the message, though its content may not be directed at them; the name comes from copies made with carbon paper on a typewriter. Like To, the addresses are visible to every recipient, and the sending program also adds them to the envelope so the copies are delivered. Reply all includes them.
The difference from To is one of intent, and the shared exposure is the same: every Cc address is shown to every recipient, so a list of customers or prospects must never be sent in Cc. RFC 5322 allows one Cc field per message, and Google asks that such single-instance fields appear only once.
Related terms
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 5322, section 3.6.3: Destination Address Fieldsrfc-editor.org
- Google, Gmail Help: Email sender guidelinessupport.google.com
All 432 terms in the glossaryThe wiki: blocklists and bounce codes