Re: [ietf-smtp] Characteristics of Isolated (or mostly-isolated) industrial IP Networks

"John Levine" <johnl@taugh.com> Sun, 05 January 2020 17:19 UTC

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Date: Sun, 05 Jan 2020 12:19:29 -0500
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From: John Levine <johnl@taugh.com>
To: ietf-smtp@ietf.org
Cc: dcrocker@bbiw.net
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Subject: Re: [ietf-smtp] Characteristics of Isolated (or mostly-isolated) industrial IP Networks
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In article <3c50a793-dd26-3254-f9e3-b642793918b7@dcrocker.net> you write:
>What else is distinctive?

I'd think that typically you know in advance a lot about what mail
each device should send.  For example, there is a printer on my desk
that sends alerts about paper jams and the like.  It only sends mail
to one preconfigured address, and the rate at which it sends mail is
limited by the mechanical parts it's reporting on.

If it sent mail to any other address, or if the message rate was much above
one a minute, we'd know something was screwed up with its mail.

R's,
John