Targets form fields with prefixes to their name, e.g. <input type="text" name="prefix_name"> it will collect all data will "prefix_" in the name, or any prefix you specify in the example.

class.formhandler.php

<?php
/**
 * FormHandler takes care of automatically collecting form data and sending the data to a specified email address
 *
 * @example:
 * $form = new FormHandler($from = 'guess@what.com', $to = 'what@isit.com', $subject = $_POST['form-name'], $post_data_prefix = 'obf_');
 */

class FormHandler {
    public $mail;
    public $post_data_prefix;
    
    /**
     * __construct()
     *
     * called on creation of an instance, sets up basic values of instance
     *
     * @param string - from address
     * @param string - to address
     * @param string - subject of mail
     * @param string - prefix of $_POST data to collect
     */
    public function __construct($from, $to, $subject, $post_data_prefix) {
        $this->mail = new PHPMailer;
        $this->mail->IsHTML(true);
        $this->mail->From = $from;
        $this->mail->Subject = $subject;
        $this->mail->Body .= "<h2 style='font-family: sans-serif; margin: 0 0 20px 0; text-align: center;'>$subject</h2>";
        $this->mail->AddAddress($to);
        $this->post_data_prefix = $post_data_prefix;
        $this->set_field_data();
        
    }
    
    /**
     * set_field_data()
     * 
     * collects $_POST data with certain string at the beginning
     * e.g. obf_ in this 
     */
    public function set_field_data() {
        // collect all the form data
        $this->mail->Body .= "<ul style='font-family: sans-serif; list-style: none; padding: 0;'>";
        foreach($_POST as $key => $value) {
            // check if value starts with $this->post_data_prefix
            if (strpos($key, $this->post_data_prefix) === 0) {
                $label = $this->generate_readable_label($key);
                
                // don't include if empty value
                if (!empty($value)) {
                    $value = nl2br($value);
                    $this->mail->Body .= "<li style='margin-bottom: 15px;'><strong>$label</strong>: <br> $value</li>";
                }
            }
        }
        
        $this->mail->Body .= "</ul>";
        echo $this->mail->Body;
    }
    
    /**
     * generate_readable_label()
     *
     * @param string - label containing dashes and prefix
     * @return string - a (hopefully?) readable label
     */
    public function generate_readable_label($label) {
        $replace = array( $this->post_data_prefix, "-");
        $label = str_replace($replace, " ", $label);
        $label = trim(ucwords($label));
        
        return $label;
    }
    
    /**
     * isSent()
     * 
     * @return boolean - result depending if mail is sent or not
     */
    public function isSent() {
        if ($this->mail->send()) {
            return true;
        }
        
        return false;
    }

}