Cannot access Namecheap email on Verizon Wireless

So I have learned that Verizon Wireless uses Infoblox for DNS security and I believe this may be related to why I can no longer access my paid private email service provided by Namecheap. A US based cloud provider that offers paid private email service. The domain for Namecheap’s private email is: privateemail.com and I have been unable to access this site from my Verizon Wireless phone for the last few days. I can access the site on my home WiFi with Frontier internet, as well as my work AT&T phone. This issue seems limited to Verizon. I have been trying to get Verizon support to help with this issue but I’ve been going in circles with their customer support agents. They don’t seem to grasp the issue lies with Verizon’s DNS not resolving the domain anymore. I am hoping someone from Infoblox can at least verify my theory that privateemail.com is on some sort of block list that is affecting Verizon Wireless customers.