On 2025-01-03 at 19:18:34 UTC-0500 (Sat, 04 Jan 2025 01:18:34 +0100) Sebastian Nielsen via Exim-users <[email protected]> is rumored to have said:
> Ooh it actually does the DNS lookups too. > It’s a no-reply address so its not supposed to have any MX. The "Null MX" convention of returning a plain '.' is described in RFC7505. It is for domains that accept no email. There is no convention that such domains should just not have any MX records, as it is still correct for senders to fall back to A/AAAA records in the absence of a MX. As it is entirely acceptable to have an A or AAAA record for a domain that doesn't have any SMTP listener on that address, an alternative that explicitly repudiates mail was seen as necessary, and it is used by many mail-handling tools. -- Bill Cole -- ## 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/
