Mouse <mo...@rodents-montreal.org> writes: >> I'm also not sure it matters if a TLS session is preceded by the ten >> bytes `STARTTLS\r\n' on the wire or not.
> In theory, it matters because the conversation is not conformant to the > protocol otherwise; a receiver-SMTP would be entirely justified in > dropping a connection which attempts to start a TLS session without > STARTTLS, and, while I don't have specific knowledge of any (I don't > use TLS), it would surprise me if there weren't implementations that > did. (Playing fast and loose with standards conformance is in large > part how email became the disaster it currently is; doing so more just > makes it worse.) I am pretty sure Taylor menat that there is no meaningful difference between: connect to 465, negotiate TLS, speak SMTP/submission inside of TLS and connect to 587, send "STARTTLS", negotiate TLS, speak SMTP/submission inside of TLS. If STARTTLS/negotation fails, error out. and I agree. Nobody is suggesting that 587 speak TLS without STARTTLS or that 465 accept STARTTLS.
