[Mailman-Developers] LTMP for incoming mail

[Brad Knowles]

At 1:29 PM -0400 9/28/06, John A. Martin wrote:

>  Is in not possible to do Postfix virtual mailbox domains _without_
>  maildir style delivery?

Probably, but I'm not sure it really buys us much of anything to have 
separate mailboxes for each list, as opposed to a queue processing 
mechanism that is generally more robust and capable of easily 
handling lots of simultaneous transactions.

>  Independently of the above and at least for Postfix, would it be
>  worthwhile looking at the Postfix policy daemon plug-in as a way to
>  query Mailman information during the rfc821 conversation and rejecting
>  a lot of messages before DATA?

That's going to have the same issues as implementing LMTP, at least 
as far as it concerns performance and ability to handle these kinds 
of operations on a large-scale/real-time basis.

>                                 Even more interesting, because of
>  perhaps being portable, might be the milter facility that appeared in
>  Postfix 2.3.  I have not yet even looked at the later so it may AFIK
>  be very wide of the mark.

Same issues for all.  The particular protocol is not particularly 
relevant to this part of the discussion.  Regardless of how you 
implement the system, it's going to have to do certain types of 
message scanning and parsing, checking against databases and/or 
blacklists, etc....  In all cases, so long as you're holding the 
sender open while you check all these things, you're going to have 
pretty much the same concerns regarding performance and scalability.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

  Founding Individual Sponsor of LOPSA.  See <http://www.lopsa.org/>.