This helpful article aims to guide IT admins on how to grant permission to users who want to use Aqua Mail. 

Start by going to this website and Configure how users consent to applications

From there you can check all the relevant settings.

You can also go into the Azure Active Directory admin center and look at those settings.

From the User settings, you can check if users are allowed or denied consent. 

In the admin consent request, you can see if there are any requests for permissions.