Question of understanding

Hello all,

I am quite new to PMG and I really like it too. Everything works as it should.

Now I would like to build a cluster with two machines and have a question about the hostnames/FQDN.


I currently have one PMG instance:

FQDN: mail.mydomain.com
Hostname: mail

My public DNS entries look like this:

Public-IP-Provider1: mx00.mydomain.com
Public-IP-Provider2: mx01.mydomain.com

PTR Record both Provider IPs: mail.mydomain.com
SMTP Banner: mail.mydomain.com

There is an OPNsense firewall in front of the PMG, which makes a DNAT on the PMG.
Currently, both MX records point to my one PMG instance.

The goal is a cluster of two instances with one MX record each.

My question now relates to how I name the two instances and whether their FQDN in particular must be resolvable in the public DNS.

Or can I name the instances as follows:

Instance 1:

FQDN: srv1.localdomain.local
Hostname: srv1

Instance 2:

FQDN: srv2.localdomain.local
Hostname: srv2

It is important to me that e-mails, whether from instance 1 or instance 2, are always sent out with the FQDN: mail.mydomain.com
and that both servers also report incoming mails with this FQDN.


Many thanks for your help