thanks for your help!
i made it now, but it dont want to work.
i renamed the test...php to email-validation.php, no i have the 3 php files in the folder:
email-validation.php
email_validation.php (untouched)
getmxrr.php
I see the form, and i think it will check the email, but there is no result on the page.
i have the code of the email-validation.php on pastebin, maybe you find out where the mistake is? (auto-delete on pastebin after 1 week)
pastebin.com/txmJ234m
Thanks!!