Re: [Emailcore] Proposed ESMTP keyword RCPTLIMIT

[Viktor Dukhovni <[e-mail]>]

> On Mar 12, 2021, at 1:46 PM, Jeremy Harris <[e-mail]> wrote:
> 
> 
> Perhaps an ESTMP keyword "RCPTLIMIT" taking parameters
> MAX=nnn
> SINGLE_DOMAIN

I think think these would be fine extensions.  Given Dave C.'s point
perhaps:

    LIMITS RCPT=nnn SINGLEDOMAIN ...

unlike SIZE or DSN there's no need for any additional keywords in the
client's MAIL or RCPT commands, this is just advisory data from the
server to the client that aids interoperability.

A sufficiently sophisticated server might even tune such limits based
on the IP reputation and EHLO name of the connecting client.

The "LIMITS" keyword would then have an IANA registry for the individual
parameters, that might not even need standards action, just expert review
and specification required?

-- 
	Viktor.