DNS problem with VestaCP server on Vultr

[balboni]

I am adapting my mail server because I noticed a lot of my emails went to spam.

I used mail-tester.com and I got this error:

We check if there is a mail server (A Record) behind your hostname vultr.guest.

You may want to publish a DNS record (A type) for the hostname vultr.guest or use a different hostname in your mail software.

I tried adding an A record. To the DNS file pointing to the rDNS I found from my server. What am I doing wrong?

[SS88]

If your hostname is vultr.guest then you need to change it.

vultr.guest is a temporary hostname, and you need a fully qualified hostname.

Follow this guide, it's for CentOS: https://www.vultr.com/docs/how-to-chang ... -on-centos

When following the tutorial, make 10000% sure you complete Step 6.