enquiry.php form only works with .com email addresses - php

Question

The form only works if the user submitting the form is using a .com email address. If the user is using a .com address I receive an email from them containing their form information (content). But, if anyone with another email address for example .co.uk submits the form, it does not send an email to myself (billy#hotmail.co.uk), please help. The enquiry.php code is below:
<?php
$email_to = "billy#hotmail.com";
$firstname = $_POST["firstname"];
$surname = $_POST["surname"];
$telephone = $_POST["telephone"];
$email = $_POST["email"];
$time = $_POST["time"];
if (empty($firstname)) {
show_error("Please fill in your Name - hit back in the browser to correct");
}
if (empty($surname)) {
show_error("Please fill in your Surname - hit back in the browser to correct");
}
if (empty($email)) {
show_error("Please fill in your Email Address - hit back in the browser to correct");
}
if (empty($telephone)) {
show_error("Please fill in your Telephone Number - hit back in the browser to correct");
}
if (empty($time)) {
show_error("Please select a collection time slot - hit back in the browser to correct");
}
$email = htmlspecialchars($_POST['email']);
if (!preg_match("/([\w\-]+\#[\w\-]+\.[\w\-]+)/", $email)) {
show_error("E-mail address not valid");
}
$email_from = $_POST["email"];
$message = $_POST["message"];
$email_subject = "Easter 2018 Order Form";
$headers =
"From: $email_from .\n";
"Reply-To: $email_from .\n";
$message =
"First Name: ". $firstname .
"\r\nSurname: " . $surname .
"\r\nTelephone Number: " . $telephone .
"\r\nEmail Address: " . $email .
"\r\nTime Slot: " . $time .
ini_set("sendmail_from", $email_from);
$sent = mail($email_to, $email_subject, $message, $headers, "-f"
.$email_from);
if ($sent) {
header("location:
http://www.billyfarroll.co.uk/thank-you.html");
} else {
echo "There has been an error sending your comments. Please try later.";
}
function check_input($data, $problem='') {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
if ($problem && strlen($data) == 0) {
show_error($problem);
}
return $data;
}
function show_error($myError) {
?>

Answer 1

OK the problem is with your regex.
The thing is that when you use this regex
([\w\-]+\#[\w\-]+\.[\w\-]+)
it will match a result on these kind of address mail
billy#hotmail.co.uk
but the matched result will be
billy#hotmail.co
because you're askin for a_word#a_word.a_word
So the email address is valid according to your code, but isn't existing
You have to recheck your regex.
Maybe try
("/.*#.*\..*/")