John C Klensin writes:
Question: Is it time to formally deprecate 821 and, in particular, the
main feature that distinguishes it: the use of HELO by SMTP clients?
We would still need to require that SMTP servers accept it, but we
would tell full-capability clients (including the client side of
relays and gateways) that HELO is obsolete.
I think a lot of people would answer "you mean it isn't already?"
One corollary of this is that we'd be telling low-capability clients,
particularly those that are part of MUA systems, that they should be
talking to Submit ports, not SMTP ones.
I beg to differ. Low-capability clients cannot effectively talk to
submit, since submit tends to demand SASL support in the client.
Arnt