[Discuss] Help with possible email/DNS setup issue?

[Daniel Barrett]

tl;dr: A domain (kidreviewz.com) has a separate mail server
(mail.kidreviewz.com). I can send mail to info at kidreviewz.com without
error, but MailChimp insists that email to the domain bounces. Is
something misconfigured on my end?

Details: My nephew's domain, kidreviewz.com, is hosted on a Linode
server, 45.79.68.11. Email for the domain is handled by a different
server, mail.kidreviewz.com (72.29.78.191). This setup seems to work:
I can send email from anyplace to info at kidreviewz.com and it arrives
at the right destination.

Here's the problem: My nephew wants to run an email announcement list
on MailChimp so the outgoing email address appears as info at kidreviewz.com.
MailChimp of course needs to verify that he owns that address, so they
must send a "verification message" to it. Within 2 seconds of sending,
MailChimp reports failure: "We're having some trouble delivering to
info at kidreviewz.com. Looks like the verification email might've
bounced."

Rather than blame MailChimp, I'd rather blame me. Did I overlook
something in the DNS (or other) setup for kidreviewz.com? I am no DNS
expert.

Here's some output from dig:

$ dig kidreviewz.com
; <<>> DiG 9.10.3-P4-Ubuntu <<>> kidreviewz.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52057
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;kidreviewz.com.                        IN      A

;; ANSWER SECTION:
kidreviewz.com.         7931    IN      A       45.79.68.11

;; AUTHORITY SECTION:
kidreviewz.com.         79931   IN      NS      ns1036.dizinc.com.
kidreviewz.com.         79931   IN      NS      ns1037.dizinc.com.

;; ADDITIONAL SECTION:
ns1036.dizinc.com.      7630    IN      A       72.29.78.192
ns1037.dizinc.com.      7630    IN      A       72.29.78.193

;; Query time: 1 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Fri Apr 05 16:43:01 EDT 2019
;; MSG SIZE  rcvd: 140


$ dig -t mx kidreviewz.com
; <<>> DiG 9.10.3-P4-Ubuntu <<>> -t mx kidreviewz.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4150
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 4

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;kidreviewz.com.                        IN      MX

;; ANSWER SECTION:
kidreviewz.com.         8380    IN      MX      0 mail.kidreviewz.com.

;; AUTHORITY SECTION:
kidreviewz.com.         79914   IN      NS      ns1036.dizinc.com.
kidreviewz.com.         79914   IN      NS      ns1037.dizinc.com.

;; ADDITIONAL SECTION:
mail.kidreviewz.com.    14095   IN      A       72.29.78.191
ns1036.dizinc.com.      7613    IN      A       72.29.78.192
ns1037.dizinc.com.      7613    IN      A       72.29.78.193

;; Query time: 1 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Fri Apr 05 16:43:18 EDT 2019
;; MSG SIZE  rcvd: 161


Thank you very much for any insights.

--
Dan Barrett
dbarrett at blazemonger.com