(3) The BuyVM box has a cron job that does a dynamic DNS lookup (via afraid.org dyndns) and sets or updates an iptables rule that only accepts port 587 traffic from my home IP

All my domains hosted on cloudflare DNS. Also each domain have letsencrypt cert.

I don't think it's DNS. See ticket #392927 for some details.

for the dns reverse proxy:

(Quote)

Seems like a DNS issue. I will look into it.

Yes, @Francisco has been offering multi-server DNS DirectAdmin licenses for a while now. He's even throwing in a VPS to go with them. And, he unlocked the DA license so it has unlimited features too

With regards to DNS only. I think I found a legitimate work around....

Please no, one just one pdns update, broke my pdns cluster due to auto updates.

DNS-only license, already in the works. Would love to be release it at the same time as the Lite license.

I wish da had a dns only plan.... the 3rd party scripts are a pain...

Sorry for the confusion, I am asking if it's possible to do the same thing with DNS server and Nginx proxy_pass by DNS reverse proxy only and how, or it must be include HTTP reverse proxy.

I don't get it, you seem to be asking for something completely different in that link. For what you asked in that link, you don't need any DNS server, you just need to add a proxy_pass line to nginx t

Yes, this is the only easy way I could find using VestaCP panel or CentOS Web Panel since you can modifiy your DNS and Nginx templates.

This looks like what you'd setup to "hide" your site behind an HTTP(s) reverse proxy: DNS server IP stays the same, but the ip of the "A RECORD" it gives is the one

Just write it yourself, it's 100 lines of code in Golang. Or looks like someone already did it for you: https://github.com/StalkR/dns-reverse-proxy

You can see it from here: https://www.cloudflare.com/learning/dns/glossary/reverse-dns/

Nope. You cant just deliver a "false" ip over DNS to mask the "real" ip. The IP has to be the "real" one or your website wont be available at all.

https://www.knot-dns.cz/docs/2.4/html/installation.html

I will make it more clear, I am trying to mask a website IP address using my DNS server, which is also called DNS Reverse proxy (If I am right).