Hi everyone.
I am ne to iRedMail.
I have a question that i could not solve it.

First of all i watched this videio. By the way i like this channel.
youtube.com/watch?v=f2bjkZWpn7s

In this tutorial.
There is a domain and a vps server.
In DNS management he pointed www, @ and mail to VPS IP This is normal.

What is my question?
For example i have nginx lemp server 188.188.188.188 and i have a web site in it.
domain = mecra.me
ip = 188.188.188.188

I wanted to install iRedMail so i bought a new server. Its ip is for example 155.155.155.155
I know email server should be use for only iRedMail so i bought a new one.

In the domain DNS management
Should i adjust IPS like this?

www  188.188.188.188
@       188.188.188.188
mail   155.155.155.155
and other record on the video.

We should not host any other site or thing except iRedMail server.
So i wonder what should DNS records be if the iRedMail is in a new server and use an existing domains (mail.mecra.me) that still an active site that hosted in an another server.

I watched some tutorials and in these there are always a new domain and new server.
For example i have a web site mecra.me and it is in 188.188.188.188 and for example  i bought a new server and what should be records?

Thanks very much