[RndTbl] email-receive blacklist?
trevor at tecnopolis.ca
Thu Apr 29 13:53:29 CDT 2021
On 2021-04-29 Colin Stanners wrote:
> I'm afraid that if I understand the situation correctly, the MXVerify
> result is not an non-error, it is a real problem, and the likely
> cause of your issue.
See the Gilbert reply. This doesn't jive with the understanding of
these 2 old hands.
> That serverfault link is unrelated, you are not sending emails only,
> this discussion is about your domain receiving email.
Ya, but its answer re: RFC5321 is correct:
2.3.5. Domain Names
Only resolvable, fully-qualified domain names (FQDNs) are permitted
when domain names are used in SMTP. In other words, names that can
be resolved to MX RRs or address (i.e., A or AAAA) RRs (as discussed
in Section 5) are permitted, as are CNAME RRs whose targets can be
resolved, in turn, to MX or address RRs.
So per RFC is the receiving domain can either resolve to MX, *or*
direct A RR (as my domain did).
5.1. Locating the Target Host
If an empty list of MXs is returned,
the address is treated as if it was associated with an implicit MX
RR, with a preference of 0, pointing to that host.
As far as I can tell, 5321 is still in force and not superseded.
I had a valid, empty (non-existent) MX record set. That should be
If you have a different understanding, feel free to RFC-enlighten us!
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