I have an email address I want to use to register to [login to view URL] with. However, their online form for registration says my email address is invalid. But my email address is valid. I have contacted their helpdesk and they said they are using a service called mailboxlayer ([login to view URL]) to validate the email address input in their registration form.
I need someone to check what is wrong with my email address server's configuration so I can tell my server maintenance staff what they must fix.