[Emailcore] Re: [Last-Call] draft-ietf-emailcore-as-28 ietf last call Secdir review

[Pete Resnick <[e-mail]>]

On 29 Apr 2026, at 17:16, Eric Rescorla wrote:

> Let's see if we can perhaps get on the same page about the current 
> state of affairs: do you believe an SMTP implementation which requires 
> STARTTLS and does not allow you to disable TLS is presently 
> conformant?

Nope. From RFC 3207:

    A publicly-referenced SMTP server MUST NOT require use of the
    STARTTLS extension in order to deliver mail locally.  This rule
    prevents the STARTTLS extension from damaging the interoperability 
of
    the Internet's SMTP infrastructure.  A publicly-referenced SMTP
    server is an SMTP server which runs on port 25 of an Internet host
    listed in the MX record (or A record if an MX record is not present)
    for the domain name on the right hand side of an Internet mail
    address.

pr
-- 
Pete Resnick https://www.episteme.net/
All connections to the world are tenuous at best