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

"John Levine" <johnl@taugh.com> Sun, 27 October 2019 01:10 UTC

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From: John Levine <johnl@taugh.com>
To: ietf-smtp@ietf.org
Cc: moore@network-heretics.com
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Subject: Re: [ietf-smtp] How to encrypt SMTP?
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In article <344aaf1f-df91-ffb9-38bc-527d159a2ca6@network-heretics.com> you write:
>>> 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.

I'm looking at my incoming and outgoing mail logs.  FWIW, the vast
majority of the outgoing mail goes over TLS.  Partly that's because a
whole lot of mail goes to a fairly small set of providers (Google,
Microsoft, Mimecast, etc.) but I see lots of TLS to small mail
servers, too.  The non-TLS mail is what you'd expect, small
unsophisiticated mail operators, mostly not in North America.

R's,
John

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