Your new systems are running 6.7.2 HF5, the system that the backup was taken from is 6.7.2 HF2.
You will have to upgrade the old system to hotfix 5 to correct this, there is no way to downgrade the system without reimaging. If the new systems are the newest hardware generation (serial number starting with J followed by 9 numbers), they are unable to run anything older than 6.7.2 hotfix 5.
The serial number of my new box starting with H folowed by 9 numbers. In order to downgrade the new box im going to reimaging it.
I'll keep you informed of my progress
thank you very much for the answer
That is also the most recent generation, just a serial number that is not very common. You will NOT be able to install a lower hotfix version on it.
Yes, it's a new box. As you said, the only way is to upgrade my IronMail production environment. It's more tedious that downgrade a insulated box, but i'm going to do it.
Wish me luck!.
Thanks you very mutch ajclements.