Wordpress: Simple Contact Form

template-contact.php

<?php
/*
Template Name: Kontakt
*/ 
?>

<?php /* other template code goes here... */ ?>

<?php 

/* response strings */
$missing_fields	= 'Bitte füllen Sie alle Felder aus.';
$email_invalid	= 'Ihre E-Mail-Adresse ist ungültig.';
$trapped	= 'Bitte diese Seite nicht per Script aufrufen.';
$error		= 'Die Nachricht konnte nicht gesendet werden.';
$success 	= 'Danke! Die Nachricht wurde gesendet.';

/* process post vars, leave honeypot raw */
$submitted	= sanitize_text_field( $_POST['scf_submitted'] );
$name 		= sanitize_text_field( $_POST['scf_name'] );
$email 		= sanitize_text_field( $_POST['scf_email'] );
$message 	= sanitize_text_field( $_POST['scf_message'] );
$honeypot 	= $_POST['scf_message2'];

/* wp_mail vars */
$mailto		= get_option( 'admin_email' );
$subject	= 'Nachricht von  ' . get_bloginfo('name');
$headers	= 'From: ' . $email . "\r\n" . 'Reply-To: ' . $email . "\r\n";

if ( $submitted ) {
	if ( $honeypot != "" ) {
		scf_response("alert-danger", $trapped);
	} else {
		if ( !$name || !$email || !$message ) {
			$alert[] = $missing_fields;
		}
		if ( !is_email( $email ) &&  $email ) {
			$alert[] = $email_invalid;
		}
		if ( empty( $alert ) ) {
			if ( wp_mail( $mailto, $subject, strip_tags( $message ), $headers ) ) {
				$alert[] = $success;
				scf_response("alert-success", $alert); 
				unset( $submitted, $name, $email, $message, $honeypot );
			} else {
				$alert[] = $error;
				scf_response("alert-danger", $alert); 
			}
		} else {
			scf_response("alert-warning", $alert);
		}
	}
}

/* output alert html */
function scf_response( $class, $alertArr ){
	$alertStr = implode( '<br>', $alertArr );
	echo '<div class="alert ' . $class .'">' . $alertStr  . '</div>';
}

?>

<form role="form" action="<?php the_permalink(); ?>" method="post">
	<div class="form-group">
		<label for="scf_name">Name</label>
		<input 
			type="text" 
			id="scf_name" name="scf_name" 
			value="<?php echo $name; ?>" 
			class="form-control"
			placeholder="Ihr Name">
	</div>
	<div class="form-group">
		<label for="scf_email">E-Mail</label>
		<input 
			type="text" 
			id="scf_email" name="scf_email" 
			value="<?php echo $email; ?>" 
			class="form-control" 
			placeholder="Ihre E-Mail-Adresse">
	</div>
	<div class="form-group">
		<label for="scf_message">Nachricht</label>
		<textarea 
			rows="4" 
			id="scf_message" name="scf_message" 
			class="form-control" 
			placeholder="Ihre Nachricht"><?php echo $message; ?></textarea>
	</div>
	<div class="form-group" style="display:none;">
		<label for="scf_message2">Nachricht2</label>
		<input type="text" name="scf_message2" name="scf_message2">
	</div>
	<input type="hidden" name="scf_submitted" value="1">
	<button type="submit" class="btn btn-primary">Nachricht senden</button>
</form>

<?php /* other template code goes here... */ ?>