G.7.9. Discussion of 'blind' copies and RCPT

[alexey.melnikov@…]

7.2. "Blind" Copies

Addresses that do not appear in the message header section may appear
in the RCPT commands to an SMTP server for a number of reasons. The
two most common involve the use of a mailing address as a "list
exploder" (a single address that resolves into multiple addresses)
and the appearance of "blind copies". Especially when more than one
RCPT command is present, and in order to avoid defeating some of the
purpose of these mechanisms, SMTP clients and servers SHOULD NOT copy
the full set of RCPT command arguments into the header section,
either as part of trace header fields or as informational or private-
extension header fields.

Suggestion from Arnt Gulbrandsen on 2007.01.24 that got lost: delete "especially" and "the full set of" -- copying the first one can be as harmful as copying all of them, at least without verifying that the addresses do appear in the headers.

John Klensin: May alto need to discuss whether that terminology is politically incorrect and suggest a replacement.

[alexey.melnikov@…]

Discussion thread:

​https://mailarchive.ietf.org/arch/msg/emailcore/hDvppQMwcYemYn2B1Yl7qX_-zfY/

[alexey.melnikov@…]

Proposal not to change the terminology (i.e. not to replace BCC with some new term/acronym).