Re: SMTP Over TLS on Port 26 - Implicit TLS Proposal [Feedback Request]

[William Herrin <bill () herrin us>]

On Fri, Jan 11, 2019 at 6:14 PM Viruthagiri Thirumavalavan
<giri () dombox org> wrote:
> > While we're at it, let's deprecate IPv4 now that IPv6 is fully deployed
>
> Come on Mr. Herrin.

Hi Viruthagiri,

If you don't want to face the hyperbole then don't stick your head in
the sand. Unless you grossly underestimate the cost of operations
change, you propose to make the spam problem worse for some nontrivial
period of time. In exchange, you offer an explanation for how a new
port will succeed where starttls fails that frankly doesn't hold
water. Any scenario where starttls is disrupted is at least as
vulnerable to a new tcp port being blocked.

Your other idea of signaling via DNS that a man in the middle is
present if the target SMTP server fails to support encryption could
have merit. I think the specific mechanism (overloading the host name)
is unwise but I'd be interested to see the concept developed further.

Regards,
Bill Herrin

-- 
William Herrin ................ herrin () dirtside com  bill () herrin us
Dirtside Systems ......... Web: <http://www.dirtside.com/>