At 17:34 -0600 on 05/01/2007, Philip Guenther wrote about Re: "for"
clause on Received: header field:
On Tue, 1 May 2007, Robert A. Rosenberg wrote:
...
The above quote was mine. I fail to see where there is any massive
disk space or bandwidth usage if implemented correctly. There HAS
to be some ultimate SMTP Server that is delivering the message to
the user's POP/IMAP Mailbox. How hard is it for THAT SMTP Server
(if not the ones that is handing the message off it it) to put the
for clause into the Received Header as it places the cloned copy of
the message into the user's mailbox? The delivery SMTP Server MUST
clone the message at that point anyway (and it takes no extra disk
space or bandwidth for the INCOMING message).
"Black box" mail store that place each message in a separate file
(such as Cyrus IMAP) usually use filesystem hardlinks such that
there's only one copy of the message on disk for any number of
recipients up to the max link-count. That space optimization
obviously can't be used if the messages aren't exact duplicates.
I admit that for THAT implementation my method will not work. I was
thinking more of the cases where each user had their own dedicated
mailbox which was carved out of their private space allocation.