Sample emails for Null MX (notaccept)

[azumakuniyuki]

https://heartbeats.jp/hbblog/2016/12/null-mx.html

% dig MX libsisimai.org
;; QUESTION SECTION:
;libsisimai.org.            IN  MX

;; ANSWER SECTION:
libsisimai.org.     300 IN  MX  0 .

• [X] Postfix 2.10 = MX: Malformed or unexpected name server reply
• [X] Postfix 3.1.0 = Domain example.com does not accept mail (nullMX))
• [X] Sendmail 8.14.5 = Host unknown (Name server: .: host not found)
• [X] Sendmail 8.16.1 = 550 Host does not accept mail
• [X] OpenSMTPD 6.0.2 = TempFail stat=No MX found for domain
• Other MTAs ?

[azumakuniyuki]

G Suite returns the following error:

** Address not found **

Your message wasn't delivered to neko@libsisimai.org because the domain libsisimai.org couldn't be found. Check for typos or unnecessary spaces 
and try again.

Learn more here: https://www.rfc-editor.org/info/rfc7505
(Warning: This link will take you to a third-party site)

The response was:

DNS Error: 80458680 DNS type 'mx' lookup of libsisimai.org responded with code NOERROR
The domain libsisimai.org doesn't receive email according to the administrator: returned Null MX https://www.rfc-editor.org/info/rfc7505