Finding Valid Email address using php

Question

i would like to develop application to get email address, and i need to send confirmation to that email id, before that i need to check whether the entered email id is valid or not. Is there any possibilities to check using php or jsp?

Answer 1

if by validate you mean checking if the string can be an email address you can use this php line

$email = filter_var($email, FILTER_VALIDATE_EMAIL);

and after that if the variable is not empty, the email address is valid (check http://php.net/filter_var)

if by validate you meant checking if it exists - you can't

Answer 2

You don't understand the matter.

The very purpose of sending confirmation email is to check if such email exists, valid and read by the user.

Do not reinvent the wheel and do not listen to local "theorists" who never used the tools they are peddling here.
Sending the confirmation email is the only reliable way to tell if such an account exists.

Answer 3

function validEmail($email)
{
   $isValid = true;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = false;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = false;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = false;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = false;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = false;
      }
      else if
(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless 
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = false;
         }
      }
      if ($isValid && !(checkdnsrr($domain,"MX") || 
 ↪checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = false;
      }
   }
   return $isValid;
}

Thanks to http://www.linuxjournal.com/article/9585

Answer 4

No reason to reinvent the wheel, Zend Framework offers a email validation library, check out the docs for more info.

Looks like you can do:

// Under EmailAddress section of docs
$validator = new Zend_Validate_EmailAddress();

if ($validator->isValid($email)) {
    // email appears to be valid
} else {
    // email is invalid; print the reasons
    foreach ($validator->getMessages() as $message) {
        echo "$message\n";
    }
}

Answer 5

Checking if a mail exist over SMTP with PHP

http://www.webdigi.co.uk/blog/wp-content/uploads/2009/01/smtpvalidateclassphp.txt

example

<?php

// the email to validate  
$email = 'joe@gmail.com';  
// an optional sender  
$sender = 'user@example.com';  
// instantiate the class  
$SMTP_Valid = new SMTP_validateEmail();  
// do the validation  
$result = $SMTP_Valid->validate($email, $sender);  
// view results  
var_dump($result);  
echo $email.' is '.($result ? 'valid' : 'invalid')."\n";  

// send email?   
if ($result) {  
  //mail(...);  
}

?>