On Fri, 27 Feb 2026, John Levine wrote:
That is submission, not SMTP. It works great from your mail program to your mail server, not between one mail server and another. That’s why SMTP needs MTA-STS or TLSA. Having written the STARTTLS code for the mail server I use, and temporarily made it impossible for my wife to get mail from her mother due to broken TLSA, I’m not guessing here.
In any event, I think I have the answer to my original question. Independent of the question of where in the session the TLS should start, or whether we understand the difference between submission and SMTP, for e-mail there's no reason to use QUIC rather than TLS over TCP. Thanks
Regards, John Levine, [email protected], Taughannock Networks, Trumansburg NY Please consider the environment before reading this e-mail. https://jl.ly
