Re: [ietf-smtp] starttls-everywhere

[Hector Santos <[e-mail]>]

On 4/1/2019 2:55 PM, Phil Pennock wrote:
> On 2019-03-31 at 22:14 +0200, [e-mail] wrote:
>> in my mind that is not a good way forward,
>> I thnk it will break up email as an internet service.
>> I would much rather go the upwards compatible path,
>> like we did for smtp/esmtp which I think has been very succcsful.
>>
>> The esmtp transition has been so successful because we designed
>> it to be so, and nobody was hurt. Transition to starttls has been very successful
>> also because it was designed to be smooth. Please don't break email!
>
> Nothing breaks except that which is _supposed_ to break.
>
> Sometimes, things are supposed to break, in the place and manner
> designed to do so safely.  This is solid engineering: make sure that
> when breakage happens, it happens safely, with minimal knock-on
> consequences.  "Never break" is the same as "never repaired".

I think we basically need to keep with the long time support for 
Public Port 25 legacy SMTP operations. It has been a blessing (high 
growth, high connectivity) and curse (the unsolicited spam, the 
potential clear text insecurity).

We can do non-public port enhancements with 587 and 465.  587 offers a 
higher level of enforcement per local/private network policies and 465 
offers implicit TLS on SMTP (SMTPS).

But let's not mess with or break public port 25 legacy SMTP 
operations.  I don't think there is a payoff there for most systems at 
most levels.

-- 
HLS