Detecting if an email is genuine

[Xurion]

If I have an email address field that the user fills in, what is the best way to detect if that email is real?

Do I simply detect if there is an @ symbol there? Or is there another way to detect if it is genuine?

Thx in advance  :)

[hostfreak]

Here is what I use, most of the time:

[code]
$email = $_POST['email'];
$regex = "^[_+a-z0-9-]+(\.[_+a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]{1,})*\.([a-z]{2,}){1}$";
if (!eregi($regex,$email)) {
  echo "Invalid Email!";
}
else {
  //do whatever
}
[/code]

[vbnullchar]

what if you want to check if the email address is really existing?

[hostfreak]

Do you mean something like:

[code]
if (empty($_POST['email'])) {
  echo "No email was entered";
}
else {
  //do whatever
}
[/code]
?

[vbnullchar]

nope i mean how can you check if the domain entered really exist

ex. vbnullchar@yahoo.com <- this is existing
someone@somewhere.com <- can u determine if somewhere.com really exist..

[HuggieBear]

Yes, you can attempt to resolve the name first by performing an MX Lookup.

For further details try googling [url=http://www.google.co.uk/search?hl=en&q=%22Validate+email%22+%2Blookup&btnG=Search&meta=]"Validate Email" +Lookup[/url]

Regards
Huggie