Hello ,
Thank you for reaching to the Mcafee.
The reason the ENS product may reaching the external Mcafee server for below reasons.
1)To take updates---- as shown in below screenshot_01.
2)To check the GTI feedback---- as shown in below screenshot_02.
3)Mcafee agent----reaching Mcafee HTTP sites to get an update as shown in the picture below_03
Try to disable these and check.
As you are using systems in the closed environment you can visit the below link, download updates and install them on epo server so that your client systems take an update from your EPO server.
https://www.mcafee.com/enterprise/en-us/downloads/security-updates.html?region=us
I hope this helps.
Let us know if you have any queries.


