How to bring a server with CentOS to the Internet?

Question

Domain Name System

Good afternoon.
Situation: There is a static IP. EXSI was installed on the physical server and a virtual machine was created.
CentOS 6.7 is installed on that machine in the future ISPmanager will be installed (to work with the company's website).
Vooot. The server is available locally, from any computer (at the office) I can connect to it via SSH.
CentOS has access to the Internet, updated and installed a couple of details, added ports to iptables (80,442,25,465,110,995,143,993,22. I don’t know why yet).
How to make the server accessible from "outside" (from any computer in almost any corner of the planet).
I'm slowpoke in this topic and I'm doing everything for the first time.
I understand you need to forward ports in the router?
Thanks
Today:
Good afternoon. SSMaker.ru/7935b31e I registered all the ports, but when checking they are closed, I registered the IP address of the PC to check there and they are still closed, they turn off the antivirus, etc. and it doesn't matter.
Can you tell me where to think?

Answer 1

You understand correctly - forward the necessary ports on the router.

Answer 2

Static IP to start with, to "from any computer, almost anywhere in the world"