Registration system

[Suchy]

I have a registration system, that gets info form a user sticks it into mysql and sends him/her confrmation email. It works, except the email confirmation.

When I enter a hotmail, gmail, yahoo... email I do not get the confirmation email.

But when I enter an email account from my website (admin@_____.org ), where the registration script is. I get the confirmation email.

 

What is wrong with this :

if($result = mysql_query($insert))
{
	$headers = "FROM: Admin <admin@____.org>";
	$msg = "Thank you for joining $name!\n\nPlease direct your browser here to confirm your account.\n\n";
	$msg .= "http://_______/register.php?confirm=$confirm";
	mail($email,"Welcome! Confirm Your Account",$msg,$headers);
}