Hi there, have a basic email domain validation script that takes a user's email domain, resolves the IP address from that and then checks that against various published blacklists. Here is how I am determining the IP:
$domain = substr(strchr($email, '@'), 1);
$ip = gethostbyname($domain);
The problem is that some email address domains, such as
[email protected], use an MX record rather than an A record, so using gethostbyname('alumni.example.net') will fail to resolve. I know when a user's email is using an MX in the email itself by using the PHP checkdnsrr function, but once at that stage am a little stuck as to how to proceed.
In theory, I could parse out the '
root' domain, i.e. 'example.net' and check it, but I've not found reliable regex that can handle this task when the user could easily have an email the format of
[email protected]...
So, any suggestions on how to best tackle this??
