Registering Users through Email Verification

This tutorial demonstrates about registering users and activating their accounts using email verification system.

Database
Sample database users table contains four columns uid, email, password, activation and status.

CREATE TABLE IF NOT EXISTS users (
uid int(11) NOT NULL AUTO_INCREMENT,
email varchar(300) NOT NULL UNIQUE,
password varchar(300) NOT NULL,
activation varchar(300) NOT NULL UNIQUE,
status enum('0','1') NOT NULL DEFAULT '0',
PRIMARY KEY (uid)
) 

HTML Code

Contains simple HTML code.

<form action="" method="post">
<label>Email</label>
<input type="text" name="email" class="input" autocomplete="off"/>
<label>Password </label>
<input type="password" name="password" class="input" autocomplete="off"/><br/>
<input type="submit" class="button" value="Registration" />
<span class='msg'><?php echo $msg; ?></span>
</form> 

db.php

Database configuration file, modify username, password, database and base url values.

<?php
define('DB_SERVER', 'localhost');
define('DB_USERNAME', 'username');
define('DB_PASSWORD', 'password');
define('DB_DATABASE', 'database');
$connection = @mysqli_connect(DB_SERVER,DB_USERNAME,DB_PASSWORD,DB_DATABASE);
$base_url='http://www.youwebsite.com/email_activation/';
?>
index.php
Contains PHP code, storing user registration values into users table. Here activation code generation using MD5 encryption.
<?php
include 'db.php';
$msg='';
if(!empty($_POST['email']) && isset($_POST['email']) &&  !empty($_POST['password']) &&  isset($_POST['password']) )
{
// username and password sent from form
$email=mysql_real_escape_string($_POST['email']);
$password=mysql_real_escape_string($_POST['password']);
// regular expression for email check
$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/';

if(preg_match($regex, $email))
{
$password=md5($password); // encrypted password
$activation=md5($email.time()); // encrypted email+timestamp
$count=mysqli_query($connection,"SELECT uid FROM users WHERE email='$email'");
// email check
if(mysqli_num_rows($count) < 1)
{
mysqli_query($connection,"INSERT INTO users(email,password,activation) VALUES('$email','$password','$activation')");
// sending email
include 'smtp/Send_Mail.php';
$to=$email;
$subject="Email verification";
$body='Hi, <br/> <br/> We need to make sure you are human. Please verify your email and get started using your Website account. <br/> <br/> <a href="'.$base_url.'activation/'.$activation.'">'.$base_url.'activation/'.$activation.'</a>';

Send_Mail($to,$subject,$body);
$msg= "Registration successful, please activate email.";
}
else
{
$msg= 'The email is already taken, please try new.';
}

}
else
{
$msg = 'The email you have entered is invalid, please try again.';
}

}
// HTML Part
?>

Send_Mail.php
Sending email function, just modify SMTP host, username and password.
<?php
function Send_Mail($to,$subject,$body)
{
require 'class.phpmailer.php';
$from       = "from@yourwebsite.com";
$mail       = new PHPMailer();
$mail->IsSMTP(true);            // use SMTP
$mail->IsHTML(true);
$mail->SMTPAuth   = true;                  // enable SMTP authentication
$mail->Host       = "tls://smtp.yourwebsite.com"; // SMTP host
$mail->Port       =  465;                    // set the SMTP port
$mail->Username   = "SMTP_Username";  // SMTP  username
$mail->Password   = "SMTP_Password";  // SMTP password
$mail->SetFrom($from, 'From Name');
$mail->AddReplyTo($from,'From Name');
$mail->Subject    = $subject;
$mail->MsgHTML($body);
$address = $to;
$mail->AddAddress($address, $to);
$mail->Send();
}
?>
activation.php

Contains PHP code, here based on activations code user status updating from 0 to 1.

<?php
include 'db.php';
$msg='';
if(!empty($_GET['code']) && isset($_GET['code']))
{
$code=mysql_real_escape_string($_GET['code']);
$c=mysqli_query($connection,"SELECT uid FROM users WHERE activation='$code'");

if(mysqli_num_rows($c) > 0)
{
$count=mysqli_query($connection,"SELECT uid FROM users WHERE activation='$code' and status='0'");

if(mysqli_num_rows($count) == 1)
{
mysqli_query($connection,"UPDATE users SET status='1' WHERE activation='$code'");
$msg="Your account is activated";
}
else
{
$msg ="Your account is already active, no need to activate again";
}

}
else
{
$msg ="Wrong activation code.";
}

}
?>
//HTML Part
<?php echo $msg; ?>

RewriteEngine On

RewriteRule ^activation/([a-zA-Z0-9_-]+)$ activation.php?code=$1
RewriteRule ^activation/([a-zA-Z0-9_-]+)/$ activation.php?code=$1 

CSS code
body
{
font-family: "Helvetica",Arial,sans-serif;
font-weight: 500;
color:#333;
}
label
{
width:100px;
display:block;
font-weight:bold;
color:#666666;
}
#main
{
margin:0 auto;
width:800px;
}
.input
{
padding:10px;
font-size:14px;
border:1px solid #999999;
width:200px;
margin-bottom:10px;
}
.button {
padding:10px;
background-color: #5fcf80 !important;
border-color: #3ac162 !important;
}
.msg
{
font-size:11px;
color:#666;
padding:10px;
}