When trying to change my email in the client area from [email protected] to [email protected], it fails and says the error message ‘The email must be a valid email address’ (By fails, I mean it reloads the page on clicking ‘Update email address’ button and shows the error at the top of the page)
I think because it is not allowed to use emails based on custom domains, just for your own security because it is possible someone hacks the server where you’re hosting your email.
You’re on point about the MX lookups, the mail validation does check if the domain name is able to receive email. But for some strange reason, the DNS resolvers on the client area server for some reason can’t resolve your domain name.
This has been fixed now and your email address should be accepted now.
I don’t know what caused the default DNS resolvers to return an error response. My first guess was that your nameservers might be malfunctioning, but I wasn’t able to confirm that anywhere else. If other places report DNS errors too, that does support the nameserver theory.