8.04 MTA?

[Steve C. Lamb]

On Tue, Jul 29, 2008 at 01:37:01PM -0400, Rashkae wrote:
> Can you clarify what you consider the 'right thing?'.. Chances are I'll
> disagree, but I'd still like to know wtf your talking about.

    Content filtering and rejection at SMTP time.  IE, check for viruses/spam
at the end of the data block and issue a 550 if either are found as a response
to the data block.

    In spite of Derek's response Postfix is qmail-esque in that it has
multiple programs to do multiple things.  Because of this the daemon which
sits on 25 and accepts mail doesn't do the content filtering.  It passes it to
something else.  However, last I checked, both postfix and qmail were
incapable of doing content filtering until it passed the message to the next
program in the chain.  However to pass to the next program in the chain they
have to accept the message.

    Once the message is accepted they are obligated to either deliver it or
issue a bounce.  Issuing a bounce on forged headers leads to extremely clogged
queues.  By issuning a 550 after the data block the onus on issuing, and
delivering, the bounce is on the remote side.  If the remote side is a virus
engine then there's no worry.  If it isn't then their clogged queue is a big
hint they might want to shut down the spammer/virus vector that is using them
as a relay.

-- 
         Steve C. Lamb         | I'm your priest, I'm your shrink, I'm your
       PGP Key: 1FC01004       | main connection to the switchboard of souls.
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