Verifying MX records?

[cryo75]

Domains like icoud.com or googglemail.com return answers but they should be incorrect mail exchanges. How can I make sure that the domain is a valid mail exchange?

[MichaCo]

I do not understand what you mean by, you got an answer and they should be incorrect?!

And I have no idea how to properly validate an email server. But you could probably just use the smpt protocol / or a mail client , and try to connect to see what the response is?
Anyways, that has nothing todo with DNS and I'm not really sure what you are asking for.