Georg v.Zezschwitz writes:
> In the ideal case:
I asked for real measurements, not fantasy measurements. Please stop
dodging the question.
> Therefore: 250-SIZE\r\n = 10 bytes (Sorry, I forgot the initial 4 bytes).
Sending EHLO to a typical sendmail host actually produces 73 more bytes
than sending HELO.
>From your message count I would guess that SIZE did in fact save some
miniscule percentage of your bandwidth. On many other hosts SIZE wastes
some miniscule percentage. Either way it's a silly optimization.
> You've made several suggestions like QMTP to save some bandwith.
No. QMTP is designed to save _time_. And it succeeds: a QMTP connection
is, on average, several times faster than an SMTP connection. The
reduction in latency is directly visible to users.
This has nothing to do with bandwidth. Mail is under 5% of the
Internet's overall traffic.
> If our customer and we both support SIZE, there is another good way to
> stop mail bombers.
No, it isn't. Mail bombers can send small messages too. Please don't
advocate broken security mechanisms; they distract attention from
serious security mechanisms.
> It looks like SIZE is probably the mostly beloved feature of ESMTP.
No. It's simply the oldest ESMTP feature advertised by sendmail. Most
people who know about it, like you, have never considered its costs, and
have never measured its actual effects.
---Dan
Smaller, faster, safer than inetd+tcpd.
http://pobox.com/~djb/ucspi-tcp.html
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