Re: [ietf-smtp] Possible cont4ibution to moving forward with RFC5321bis SMTP

[Keith Moore <[e-mail]>]

On 1/1/20 12:55 PM, John Levine wrote:

> In article<[e-mail]>  you write:
>> (I do also wonder how many existing SMTP servers can handle TLS with
>> client certificates, because that seems like that would also be a
>> recommendation worth considering.)
> Several, as noted, and there are some old patches for qmail to do it, too.
>
> But once again, this is submission, not SMTP.  A client certificate is
> a plausible way for a submission client to authenticate itself to the
> submission server.

Agreed that client certs can be useful for mail submission 
authentication.   But I was wondering about the feasibility of migrating 
to use of client certificates for relay to mail exchangers, i.e. across 
administrative mail domain boundaries.

Keith