Bcc - Blind Carbon Copy

BCC example

A Bcc (blind carbon copy; also BCC) is a copy of an email message sent to a recipient whose email address does not appear (as a recipient) in the message.

How Does Bcc Compare to To and Cc?

By being hidden, Bcc recipients differ from To and Cc recipients, whose addresses do appear in the respective header lines. Every recipient of the message can see all the To and Cc recipients, but only the sender knows about Bcc recipients.

If there is more than one Bcc recipient, they do not know about each other either, and they will typically not even see their own address in the email header lines.

(Note that the underlying Internet standard that specifies email format, RFC 5322, is unclear about how hidden Bcc recipients are from each other: it leaves open the possibility that all Bcc recipients get a copy of the message (a message distinct from the copy To and Cc recipients get) where the full Bcc list including all addresses is included. This is highly uncommon, though.)

How and When Should I Use Bcc?

Limit your use of Bcc to essentially one case: to protect the privacy of recipients when you send to a group whose members do not know each other.

Other than that, it is best not to use Bcc and add all recipients to the To and Cc fields instead. Use the To field for people who are direct recipients and the Cc field for people who get a copy for their notice (but who need not themselves take action in response to the email).

How Does Bcc Work?

With Internet email, when an email message is delivered, its recipients are specified independently from the email headers you see as part of the message (the To, Cc and Bcc lines).

If you add Bcc recipients, your email program may take all addresses from the Bcc field combined with the addresses from the To and Cc fields and specify them as recipients to the mail server it uses to send the message.

While the To and Cc fields are left in place as part of the message header, the email program then removes the Bcc line, however, and it will appear blank to all recipients.

It is also possible for the email program to hand the email server the message headers as you entered them and expect it to deduce Bcc recipients from them. The mail server then will send each of the addresses a copy, but delete the Bcc line itself or at least blank it out.

Also Known As: Blind carbon copy

Alternate Spelling: BCC

Example: I bcced (also: BCCed, bcc'd and bcc:ed) Ron on this message, but I think it is better if Mary does not know.