From: Stuart Henderson <stu@spacehopper.org>
Subject: Re: smtpd: implement RFC9422 LIMITS extension announcement
To: Martijn van Duren <openbsd+tech@list.imperialat.at>
Cc: tech@openbsd.org
Date: Wed, 11 Mar 2026 12:59:31 +0000

On 2026/03/11 00:18, Martijn van Duren wrote:
> While I haven't seen this in the wild, it might be nice to announce our
> limits to the world. RFC9422 specifies 3 limits that can be announced:
> MAILMAX, RCPTMAX, and RCPTDOMAINMAX. RCPTDOMAINMAX isn't a feature we
> support as far as I'm aware, but MAILMAX, and RCPTMAX are implemented,
> so why not announce them and save everybody a bit of time where
> supported.

It doesn't strike me as something that will be very popular with mail
providers, however exim and sendmail do support it.