Sending random number to email PHP - php

Question

i am trying to send a random number to an email but unable to this is the code that i have been able to come up with so far
please help if possible
sendmail.php
$to = $_POST['email'];
$header ='From:admin#domain.com';
$subject ='Verification Code';
if(empty($to))
{
echo "Email is Empty";
}
else
{
if (mail($to,$subject,$message,$header)){
echo 'Check Your Email FOr verfication code';
}
else{
echo 'Failed';
}
}
index.php
<form action = "register.php" method="POST">
<p>Username</p>
<input type="text" name="username" maxlength="40" value='<?php if(isset($username)) echo $username ?>'"><br>
<p>New Password</p>
<input type="password" name="password">
<p>email</p>
<input type="text" name="email" maxlength="40" value='<?php if(isset($email)) echo $email ?>'"> <br><br>
<input type="submit" value="Register"> <br><br>
</form>

Answer 1

In form(index.php)
<form action="sendmail.php" method="post">
<lable>email</lable>>
<input type="text" name="email" maxlength="40">
<br>
<input type="submit" value="Register">
</form>
In sendmail.php
$rand= rand(10, 20)// random number generator
$to = $_POST['email'];
$header ='From:admin#domain.com';
$subject ='Verification Code';
$message = "Your Random number is";
$message .= $rand;
$message .= "Thank you-Admin";
if(empty($to))
{
echo "Email is Empty";
}
else
{
if (mail($to,$subject,$message,$header)){
echo 'Check Your Email FOr verfication code';
}
else{
echo 'Failed';
}
}

Answer 2

You forgot to add semicolon at the end of first line
$rand= mt_rand(100000, 999999)
It should be
$rand= mt_rand(100000, 999999);

Answer 3

I think the hosting service that You're using does not accept sending using mail() functions. Maybe for security reasons to prevent virus-like php scripts to send spams from Your account.
So create admin#domain.com email account and using PHPMailer send Your email:
require __DIR__.'/phpmailer/PHPMailerAutoload.php';
$mail = new PHPMailer;
$mail->isSMTP();
$mail->Host = 'smtp.hostname.com';
$mail->SMTPAuth = true;
$mail->Username = 'no-reply#domain.com';
$mail->Password = 'secret';
$mail->SMTPSecure = 'tls';
$mail->Port = 587;
$mail->setFrom('admin#domain.com');
$mail->addAddress($to);
$mail->isHTML(true);
$mail->Subject = $subject;
$mail->Body = $body;
if(!$mail->send()) {
echo 'Message could not be sent.';
echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
echo 'Message has been sent';
}
download link and examples here: https://github.com/PHPMailer/PHPMailer