Re: The need for two headers

On Sun, Feb 08, 2004 at 09:42:02AM -0600, Steven F Siirila wrote:
> 
> Be careful here.  If I send a message to multiple recipients at a given site,
> all as "Bcc:" or equivalent, I may not want all of the recipients to see the
> complete delivery path information if it's going to contain all of the
> recipient's addresses.  That would defeat the purpose of "Bcc:".

I don't think so. 

Bcc should be a function of the MUA as today which says: Write
this address on an envelope (outer metadata), but not to the inner
header, which is sent to every recipient.

This has some consequences for the metadata structure. 

When we send a message to several recipients, one message body
(and inner header) could be attached to a bundle of separate outer
headers (routing metadata) for every single recipient. Whenever 
one MTA decides to choose different routes for the given recipients, 
then the routing metadata are to be split and the body copied.

This means that we would need two different Bcc mechanisms. 
Both of them mean that the recipients do not see (in the outer header/
routing metadata or in the message header) the Bcc addresses.

The weak Bcc could mean to leave the recipients bundled until 
different routes need to be taken. (Advantage: Less
traffic. Disadvantage: MTAs see the Bcc address)

The strong Bcc would mean that the sending MUA launches distinct
messages from the beginning of the path.


regards
Hadmut