MIAB

On Linode:

a.) Ubuntu 14.04 with Mail in a Box installed.

b.) my subdomains, mail.example.com, sub.example.com, sub2.example.com.

Google:

a.) I registered my domain with Google Domains.

b.) My website, example.com, is on Google Cloud Platform.

Three DNS Managers, oh my!

a.) Linode has a DNS Manager

b.) Mail in a Box has a Custom and External DNS webpage

c.) Google Domains has a DNS manager

I am struggling to configure all three. I am not sure if I even need to configure all three. Any suggestions? Many thanks!

DNS isn't configured properly for this domain: DNS resolution failed

(A: All nameservers failed to answer the query mail.example.com.

IN A:

Server x UDP port 53 answered SERVFAIL;

Server x UDP port 53 answered SERVFAIL;

Server x UDP port 53 answered SERVFAIL;

Per Mail in a Box's Community Forum:

"Mail-in-a-Box will be the only DNS server you will need to configure. Just use the guide[0] to point your Google Domain to your Box on Linode and setup rDNS on Linode. [0] https://mailinabox.email/guide.html"