On 8. januára 2025 10:16:09 UTC, Viktor Dukhovni via Exim-users <[email protected]> wrote: >On Wed, Jan 08, 2025 at 09:59:38AM +1000, Martin D Kealey via Exim-users wrote:
>As for NODATA, while legitimate mail domains with just A/AAAA records >and no MX records are are a small minority, they exist, and should >not be rejected without understanding the impact on your own traffic. AFAIK that is exactly purpose of Null MX, to prevent fallback to A/AAAA. The name has MX (thus no NoData), but it contains invalid hostname (a dot). Or in other words to distinguish existing names without SMTP service from those relying (perhaps by mistake) on A/AAAA fallback. BTW, RFC exactly mentions, that by publishing Null MX one have to be prepared to email rejection, if that domain is used as address in MAIL FROM: command and/or in From: header. regards -- Slavko https://www.slavino.sk/ -- ## subscription configuration (requires account): ## https://lists.exim.org/mailman3/postorius/lists/exim-users.lists.exim.org/ ## unsubscribe (doesn't require an account): ## [email protected] ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
