Warning: preg_match(): No ending delimiter ‘^’ found in

we are receiving this error:

Warning: preg_match(): No ending delimiter ‘^’ found in /home/goose/public_html/wp-content/themes/goose/partials/contact.php on line 32
Please enter a valid email address

http://thegoosedarien.com – using the contact form, we receive this error message when submitting.

No idea how to resolve this. What is missing from the code?

<?php 

$asset_path = get_bloginfo('template_url');

?>

<div class="left">

<span class="main-title">
    <?php _e( 'Contact Us', 'goose' ); ?>
</span>

<?php 

    if($_SERVER['REQUEST_METHOD'] === 'POST') { 

        $flag = 1; 

        echo '<div class="notice">';

        if($_POST['submission_name'] == '') { 
            $flag = 0; 
            echo "Please enter your name<br />";
        } else if(!preg_match('/[a-zA-Z_x7f-xff][a-zA-Z0-9_x7f-xff]*/', 
$_POST['submission_name'])) { 
            $flag=0; 
            echo "Please enter a valid name<br />"; 
        } 

        if($_POST['submission_email'] == '') { 
            $flag = 0; 
            echo "Please enter your email address<br />";
        } else if(!preg_match("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a- 
   z0-9-]+)*(.[a-z]{2,3})$", $_POST['submission_email'])) { 
            $flag=0; 
            echo "Please enter a valid email address<br />";
        } 

        if($_POST['submission_message'] == '') { 
            $flag = 0; 
            echo "Please enter a message<br />";
        }

        if (empty($_POST)) { 

            echo "Sorry, your submission is invalid - please try again!"; 
            exit; 

        } else { 

            if($flag == 1) { 
                wp_mail(get_option("admin_email"), 
trim($_POST[submission_name])." sent you a message from " . 
get_option("blogname"), stripslashes(trim($_POST[submission_message])),"From: ".trim($_POST[submission_name])." <".trim($_POST[submission_email]).">rnReply-To:".trim($_POST[submission_email]));
                echo "Submission successfully sent!<br />";
            }

        }

        echo '</div>';

    }

?>

<form method="post" parsley-validate parsley-show-errors="false" 
id="contact-form">
    <div class="line">
        <label for="name"><?php _e( 'Your Name', 'goose' ); ?></label>
        <input type="text" id="name" name="submission_name" required="required" />
    </div>
    <div class="line">
        <label for="email"><?php _e( 'Your Email', 'goose' ); ?></label>
        <input type="text" id="email" name="submission_email" required="required" parsley-type="email" />
    </div>
    <div class="line">
        <label for="msg"><?php _e( 'Message', 'goose' ); ?></label>
        <textarea id="msg" cols="10" rows="10" name="submission_message" required="required"></textarea>
    </div>  
    <button>
        <span><?php _e( 'Submit', 'goose' ); ?></span>
    </button>
</form>