Re: [ietf-smtp] EHLO domain validation requirement in RFC 5321

John Levine <johnl@taugh.com> Sun, 04 October 2020 21:46 UTC

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Date: 4 Oct 2020 17:46:02 -0400
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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] EHLO domain validation requirement in RFC 5321
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In article <945d2baf-c5a9-fb9e-4563-93dff1824102@network-heretics.com> you write:
>> *  Do not host your email system ‘in the cloud’
>I'm not sure what this actually means or why it's still a bad idea.   
>Cloud hosting makes a lot of sense for various reasons.

It's a bad neighborhood, since you can expect your neighbors to be
poorly managed botted spam-spewing web servers. It varies by cloud
provider but the median is pretty bad.

>> *  Make sure that your IP address is not listed in the PBL
>
>I suspect that this is something that sites will have less and less 
>control over in the future, ...

It would likely be helpful to spend a few moments reading about what
the PBL is. "Less and less control" is very unlikely.

>> *  Accept reports of problems with your systems
>Is there a more recent standard for doing so than postmaster@?

Um, RFC 2142 published 23 years ago.

R's,
John