If I have :
domainA.com/out.php :
Is it possible to ge
I am not sure what you mean by
from domainC.com?
but in PHP you can call gethostbyname('domainB.com') which will give you the IP of domainB.com from domainA.com/out.php
gethostbyname('domainB.com')
domainA.com/out.php