Re: [ietf-smtp] [Emailcore] Proposed ESMTP keyword RCPTLIMIT

John R Levine <johnl@taugh.com> Mon, 19 April 2021 21:58 UTC

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Date: 19 Apr 2021 17:58:35 -0400
Message-ID: <4fe09f20-66ee-b3c-94bb-be654b8354bc@taugh.com>
From: "John R Levine" <johnl@taugh.com>
To: "Ned Freed" <ned.freed@mrochek.com>
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Subject: Re: [ietf-smtp] [Emailcore] Proposed ESMTP keyword RCPTLIMIT
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On Mon, 19 Apr 2021, Ned Freed wrote:
> I'm especially interested in people's thoughts on rate limits. The problem I
> have with rate limits is, well, how to express them. ...

A little surveying might be in order.

I see that Postfix lets you set both the numerator and denominator of the 
rate limit, but the denominator defaults to a minute.  It has separate 
rate limits for connections and messages.

Exim also lets you set both, the examples use an hour.  The documentation 
says that if you use a large interval that lets people send bursts.

Regards,
John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly