Leslie Mikesell <les@Mcs.Net> wrote:
>According to Dave Sill:
>> Right, and it's really not the MTA's job to throw away messages on the
>> user's behalf.
>All of the mainstream MTA's think otherwise.
So what? That doesn't make it right. Users subscribed to multiple
lists might want duplicates messages, especially if they automatically
file them in subfolders.
>> Duplicate elimination is an MUA/MDA function. Procmail,
>> for example, can do it via recipes like:
>Only the MTA can do it correctly, since it is the only thing that
>knows the duplication came from expanding the envelope addresses
>on a single message.
Unfortunately, if the MTA does it, the recipient has no control over
>Later guesswork based on Message ID may
>work sometimes but it may discard information from forwarded and
>improperly handled messages.
Nothing's perfect. That's why I file my duplicates in a "dupes" folder
instead of just throwing them out.
>Qmail has no consideration for delivery issues involving address groups.
>Other MTA's do. If you gateway to uucp, fax,
qmail can do both of those. What does that have to do with address
>or a local storage system
>that is capable of processing a single copy for multiple users, letting
>qmail touch the message will destroy that capability.
I really don't care how J Random Remote Site stores its messages, or
whether qmail makes it use a few extra files occasionally. The remote
site chose to use storage method that is more efficient for multi-RCPT
messages, but that doesn't obligate me to send them there that way.
>Likewise for duplicate elimination.
I don't see what single-RCPT delivery has to do with list duplicate
elimination. Each list delivery is a separate set of MAIL/RCPT.../DATA
transactions, regardless of the MTA. If "user@host" is on "list1" and
"list2", and a message is sent to both lists, he'll get copies with
"list1-owner" and "list2-owner" in the return path. Only Majordomo
could conceivably see that "user@host" is on both lists (and only if
the addresses are identical) and contruct a temporary list with only
the unique addresses. But then how would it handle bounces? If
"user@host" bounced, would list1-owner or list2-owner be notified? Or
would you set something up to notify both? Sounds complicated.
>> I have list mail delivered to separate mailboxes using qmail's
>> extension addresses, e.g., email@example.com goes to
>> ~/Mail/spool/listname. If someone replies to a message I post to a
>> list and cc's firstname.lastname@example.org, I'll get two copies: one in my
>> main mailbox and another in the list mailbox. I want this behavior.
>This has nothing to do with duplicate elimination.
Yes it does: the messages are duplicates.
>These addresses are not duplicates after expansion.
OK, then, what if I have a procmail recipe that looks at the envelope
return path to properly file list mail? Then the addresses *are*
duplicates after expansion, but I *still* want both copies because the
headers are different.