PHP form is not successfully submitting getting custom error - php

Question

My PHP form isn't submitting successfully. I keep getting the custom error that I wrote ('Oops there was a problem. Please try again").
any help would be greatly appreciated. I'm totally new to PHP so I'm thinking maybe some of my php variables are linked wrong and arent connecting with my mailer-new.php file?
Thanks in advance,
<section class="form-body">
<form method="post" action="mailer-new.php" class="contact-form" >
<div class="row">
<?php
if ($_GET['success']== 1){
echo " <div class=\"form-messages success\"> Thank you!
your message has been sent. </div>";
}
if ($_GET['success']== -1){
echo " <div class=\"form-messages error\"> Opps there was a
problem. Please try again </div>";
};
?>
<div class="field name-box">
<input type="text" name="name" id="name" placeholder="Who
Are You?" required/>
<label for="name">Name</label>
<span class="ss-icon">check</span>
</div>
<div class="field email-box">
<input type="text" name="email" id="email"
placeholder="name#email.com" required/>
<label for="email">Email</label>
<span class="ss-icon">check</span>
</div>
<div class="field msg-box">
<textarea name="message" id="msg" rows="4"
placeholder="Your message goes here..."/></textarea>
<label for="message">Msg</label>
<span class="ss-icon">check</span>
</div>
<input class="button" type="submit" value="Send"/>
</div>
</form>
</section>
MAILER.PHP
<?php
// Get the form fields, removes html tags and whitespace.
$name = strip_tags(trim($_POST["name"]));
$name = str_replace(array("\r","\n"), array(" ", " " ), $name);
$email = filter_var(trim($_POST["email"]), FILTER_SANITIZE_EMAIL);
$message = trim($_POST["message"]);
// Check the data.
if (empty($name) OR empty($message) OR !filter_var($email, FILTER_VALIDATE_EMAIL)) {
header("Location: http://www.conallen.ie/index.php?
success=-1#form");
exit;
}
// Set the recipient email address. Update this to YOUR desired email address.
$recipient = "allenconallen46#gmail.com";
// Set the email subject.
$subject = "New contact from $name";
// Build the email content.
$email_content = "Name: $name\n";
$email_content .= "Email: $email\n\n";
$email_content .= "Message:\n$message\n";
// Build the email headers.
$email_headers = "From: $name <$email>";
// Send the email.
mail($recipient, $subject, $email_content, $email_headers);
// Redirect to the index.html page with success code
header("Location: http://www.conallen.ie/index.php?success=1#form");
?>

Answer 1

This code works correctly in my local machine, even though email is not sent response messages are coming correctly. The changes I have done is changed the host name and made the two lined header redirect into one line in the failed response. Also you have mentioned in the HTML the file name as action="mailer-new.php" and the file name mentioned in the question as MAILER.PHP. Are they same in the code?
To check whether the mail is sent or not remove the header redirect and update like this. If you are getting a failed response means mail is not configured in your server.
if(mail($recipient, $subject, $email_content, $email_headers)) {
echo "mail sent";
} else {
echo "mail sent failed";
}
Alternatively you can use the SMTP for sending email. You can use a library called PHP Mailer and can use any of the valid email address like a gmail account. Please have look at this question if that's the case
Sending email with PHP from an SMTP server