[sylpheed:37305] Re: Email standard for BCC behaviour

I just saw this. Thank you!

RFC 5322 is described as an "update" of RFC 2822. It also says in section 3.6.3, 
"The "Bcc:" field (where the "Bcc" means "Blind Carbon Copy") contains addresses 
of recipients of the message whose addresses are not to be revealed to other 
recipients of the message."

So this seems clear, but then RFC 5322 muddies the waters a bit by saying:

"In the second case, recipients specified in the "To:" and "Cc:" lines each are 
sent a copy of the message with the "Bcc:" line removed as above, but the 
recipients on the "Bcc:" line get a separate copy of the message containing a 
"Bcc:" line.  (When there are multiple recipient addresses in the "Bcc:" field, 
some implementations actually send a separate copy of the message to each 
recipient with a "Bcc:" containing only the address of that particular recipient.)"

As written, this is ambiguous, and seems to suggest that "other implementations" 
might actually keep the entire BCC line with all listed addresses. Which 
violates the principle that BCC addresses "are not to be revealed to other 
recipients of the message."

In interpreting this RFC, I would urge that principle to take priority, that is, 
BCC addresses should never be revealed to other recipients, even other 
recipients on the BCC line.

Jeremy

On Thu Jul 25 2024 3:07 AM, Anton Shepelev wrote:
> Jeremy Cook:
> 
>> See RFC 2822 section 3.6.3.
> 
> Obsoleted by RFC 5322 .
>