I have an older exchange server which is working without a problem on my current ISP. I had to switch ISP's recently and my old ISP will be disconnected shortly.
Unfortunately, even though I WAS told my new ISP can provide rDNS for my on-premises email server, I am now being told they cannot.
I have a "persistent-IP" which is ALMOST a static public IP, but it must be from a block of public IP's they have in which I am probably being natted.
So, is there a way to setup a third-party rDNS so my emails from my on-premises server do not end up in spam or bounce?