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Re: [ietf-smtp] How to encrypt SMTP?

Keith Moore <moore@network-heretics.com> Sun, 27 October 2019 00:36 UTC

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To: John Levine <johnl@taugh.com>, ietf-smtp@ietf.org
References: <20191027002554.260ABD7437F@ary.qy>
From: Keith Moore <moore@network-heretics.com>
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Date: Sat, 26 Oct 2019 20:36:23 -0400
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Subject: Re: [ietf-smtp] How to encrypt SMTP?
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On 10/26/19 8:25 PM, John Levine wrote:

>> Yes but IMO we should be moving toward a world in which TLS is mandatory for SMTP relay.    Clear guidance to implementors
>> and operators on what TLS versions, cert algorithms, and ciphersuites a client and server should support, might help us get there.
> I don't think that's the problem.  I don't see any SMTP TLS failures other than from spambots.
That sounds good, but I'd like to understand more precisely what you're 
observing.
>> (perhaps as a stepping stone, cleartext mail relay could be pessimized ...
> We already have mta-sts, which says that cleartext is forbidden for
> the domains it's published for.  Why reinvent another wheel?

Maybe it's not necessary, but I don't know how widely mta-sts is being 
required.   What are the barriers to server operators turning on MTA-STS 
everywhere?

Keith

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