Problem: I am getting a valid email not available error when creating user for uncommon email domain

Problem: I am getting a valid email not available error when creating user for uncommon email domain.

My goal is to integrate Moodle lms and adobe connect with "xxx@xxxx.ganzilis" mail addresses.

My Adobe Connect server does not have an internet connection. It works on my local network.

How can I add my domain to allowed domains in adobe connect server?

For example; Like ".volvo", ".gmail".