Need a bit of explanation please

[Mr P!nk]

Can someone tell me how this checks the domain?

 

does it scan the net or just check to see if the address is a valid one? ???

 

This code was found http://www.phpfreaks.com/quickcode/Function-to-check-for-valid-email-and-domain/451.php?higlight=email+

 

I'm asking this because i need to make sure no spammers add themselves to our email newsletter.

 

function checkEmail($email) {
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    if(preg_match("/^( [a-zA-Z0-9] )+( [a-zA-Z0-9._-] )*@( [a-zA-Z0-9_-] )+( .[a-zA-Z0-9_-] +)+$/" , $email)){
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    list($username,$domain)=split('@',$email);
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        if(!customCheckDnsrr($domain)){
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           return false; }
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      return true;
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     }
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return false;
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}
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function customCheckDnsrr($host,$recType='') {
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    if(!empty($host)) {
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        if($recType=='') $recType="MX";
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          exec("nslookup -type=$recType $host",$output);
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          foreach($output as $line) {
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            if(preg_match("/^$host/", $line)) {
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            return true;}
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         }
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      return false;
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     }
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return false;
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}
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/////// The php to check form
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// Check for email and verify
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        // If empty input echo error
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        if (empty ($_POST['email'])) {
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            $email = FALSE;
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            echo 'Please enter a email address!<br />';
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        } else {
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            // Check to make sure its a valid email, and already exists
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            if (eregi ("^[[:alnum:]][a-z0-9_.-]*@[a-z0-9.-]+.[a-z]{2,4}$", 
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            stripslashes(trim($_POST['email'])))) {
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                $email = $_POST['email'];
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                $check_email = "SELECT email FROM table WHERE email='$email'";
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                $result = mysql_query($check_email) or die (mysql_error());
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                    // If username exists echo taken error
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                    if (mysql_num_rows($result) > 0) {
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                        $email = FALSE;
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                        echo 'That email is already being used!<br />';
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                    } else {
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                    // Check to see if emails match
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                        if ($_POST['email'] == $_POST['email_verify']) {
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                            $email = trim($_POST['email']);  
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                            if (!checkEmail($email)) { 
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                                echo 'Invalid email address!<br />';
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                            } else {
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                                $email = TRUE;
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                                $email = $_POST['email'];
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                            }
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                        } else {
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                            $email = FALSE;
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                            echo 'Your email address did not match!<br />';} }
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            } else {
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            // If email is not valid echo error
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                $email = FALSE;
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                echo 'That is not a valid email address!<br />';}
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        }
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/// This all uses boolean true and fasle... to just continue do 
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if ($email = TRUE) {
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echo 'Thank You';
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} else {
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            echo 'Please try again!<br />';}
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Thanks in advance Ladies and gentlemen 

[MadTechie]

it check if the domain is a valid name for a domain, it doesn't check to see if it exists for example

 

www.phpfreaks.com will work but phpfreaks.chimps will fail

but www.wearenotfreaks.com will works (just it doesn't exist)

 

i think thats what you were asking

[Mr P!nk]

yea that's what i was getting at.

 

is there anything i can use/implement into my coding that stops spammers adding themselves to our database?

 

i get email notifications every time someone registers of course but I don't have the time to cross check them all.

 

 

thanks 

 

[MadTechie]

how do you know if their a spammer ?

thats the first question as soon as you know that you can code for it..

[Mr P!nk]

Hmmm true.

 

i guess i could always use a validation process to which the registrar has to wait for me to activate them to which i then know if im going to be spammed.

 

any ideas for what to look for in spammers addresses? e.g an invalid domain/url.

 

but even then i get spam from people using email addresses of clients with valid domains.

 

!!! Damn all you spammers why do you make our lives so difficult ?!?!?!

 

Thanks anyway

MadTechie

you have been rather helpful

[wildteen88]

You could use one of the gethostby* functions to verify the domain name. However using gethostby* can be be slow.

[Mr P!nk]

You could use one of the gethostby* functions to verify the domain name. However using gethostby* can be be slow.

 

Yea that was my initial thought, and yes your right (well you are a genius) it was way to slow, i imagine people would think there was a problem after entering there address and close their browser therefore annoying them.

 

Thanks for your input though

appreciated