Re: [ietf-smtp] Endless debate on IP literals

[Dave Crocker <[e-mail]>]

On 1/2/2020 9:03 AM, John R Levine wrote:
> Agreed.  I do think there's a few things like STARTTLS that need to move 
> into the mandatory core, but not many.


To beat this point into the ground, just to make sure there is no 
confusion:  since starttls isn't in rfc5321...

The target documents would be:

    1) Astreamlined rfc5321bis

    2) A document specifying requirements for Exterior MTAs, which would 
include mandating rfc5321bis, starttls, ...

    3) Possibly a document specifying requirements for Interior MTAs?


My impression is that there's some amount of desire to restrict use of 
IP literals in EHLO [*] to interior mtas, and prohibiting them from 
exterior mtas.

If that assessment is roughly correct, it would mean that rfc5321bis 
would specify /only/ support for domain names in the EHLO command, with 
an Interior MTA document specifying an enhancement to the command, to 
allow use of IP literals.


d/

[*] whether and where to deprecate HELO is a separate issue needing 
similar consideration for scope of use.

-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net