initialisation error while installing Acrobat DC. Due to DPI SSL

We have recently enabled Deep Packet Inspection over SSL, on our firewall for increased security. Since then, i can no longer install Acrobat (i have not been able to try any other Adobe products, but expect i would find the same).
I am able to download the installer, but as soon as it starts, i get an 'initialisation error', and the install fails.
To verify that it is the DPI causing the issue, i have temporarily disabled it, the install then succeeds. Turning off our internet security every time we need to do an install or update is not a long term solution.
All I need is a URL (or more than one) to add to the exclusions on the DPI, to allow the install to complete.
I have tried adding *.adobe.com, but that did not work, which suggests that the install process calls back to another internet location.
Has anyone had a similar situation, did you find a solution?