On 3/5/2020 11:28 AM, Hector Santos wrote:
I used the reply group:
1yz Positive Preliminary reply
I had forgotten that RFC5321 had removed this 1yz code.
All because of the 1yz potentially used as a "preliminary" multiple
lines "1yz-" response before the final response was issued and a
possible legacy 821 client that looked only at the first response line
because it didn't expect multiple lines.
I don't fully recall the discussions. While I would had accepted the
decision for backward compatibility reasons over a decade ago, I am
pretty sure I would of been somewhat disappointed by the removal of
"1yz Positive preliminary reply" codes, removing even the possibility
of a keep alive concept. Today speeds allow for fast data processing,
so even today, 5, certainly 10 minutes of idle timeout is outdated and
probably should be a design taboo today. If we don't want ESMTP 2821
clients to use 1yz, well, maybe for RFC5321bis, we can lower the
timeouts. I already do for after a successful transactions where there
is additional 5 minutes wait for a new transaction. I reduced to less
than 1 minute to because clients from the BIG boys were 99.9% of the
time holding up my servers and never doing a 2nd MAIL transaction. So
wcSMTP will drop clients who chews up available mail service time from
the server threads.
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