change

    function send($subject="no title",$body="No message specified", $receiver='', $attachments = array() ) {
        //TODO add an EM_Error global object, for this sort of error reporting. (@marcus like StatusNotice)
        global $smtpsettings, $phpmailer, $cformsSettings;
        $subject = html_entity_decode(wp_kses_data($subject)); //decode entities, but run kses first just in case users use placeholders containing html
        if( is_array($receiver) ){
            $receiver_emails = array();
            foreach($receiver as $receiver_email){
                $receiver_emails[] = is_email($receiver_email);
            }

            $emails_ok = !in_array(false, $receiver_emails);
        }else{
            $emails_ok = is_email($receiver);
        }

        if( get_option('dbem_smtp_html') && get_option('dbem_smtp_html_br') ){
            $body = nl2br($body);
        }
        if ( $emails_ok && get_option('dbem_rsvp_mail_send_method') == 'wp_mail' ){
            $from = get_option('dbem_mail_sender_address');
            $headers = get_option('dbem_mail_sender_name') ? 'From: '.get_option('dbem_mail_sender_name').' <'.$from.'>':'From: '.$from . "\r\n";
            $headers .=  apply_filters('em_extend_email_headers', '', $subject);

            if( get_option('dbem_smtp_html') ){ //create filter to change content type to html in wp_mail
                add_filter('wp_mail_content_type',create_function('', 'return "text/html";'));
            }

            $attachments =  apply_filters('em_email_attach_file', $attachments, $subject);
            $send = wp_mail( $receiver, $subject, $body, $headers, $attachments );

            if(!$send){
                global $phpmailer;
                $this->errors[] = $phpmailer->ErrorInfo;
            }
            return $send;
        }elseif( $emails_ok ){
            $this->load_phpmailer();
            $mail = new PHPMailer();
            //$mail->SMTPDebug = true;
            if( get_option('dbem_smtp_html') ){
                $mail->isHTML();
            }
            $mail->ClearAllRecipients();
            $mail->ClearAddresses();
            $mail->ClearAttachments();
            $mail->CharSet = 'utf-8';
            $mail->SetLanguage('en', dirname(__FILE__).'/');
            $mail->PluginDir = dirname(__FILE__).'/phpmailer/';
            $mail->Host = get_option('dbem_smtp_host');
            $mail->port = get_option('dbem_rsvp_mail_port');
            $mail->Username = get_option('dbem_smtp_username');
            $mail->Password = get_option('dbem_smtp_password');
            $mail->From = get_option('dbem_mail_sender_address');
            $mail->FromName = get_option('dbem_mail_sender_name'); // This is the from name in the email, you can put anything you like here
            $mail->Body = $body;
            $mail->Subject = $subject;
            //add attachments
            if( is_array($attachments) ){
                foreach($attachments as $attachment){
                    $att = array('name'=> '', 'encoding' => 'base64', 'type' => 'application/octet-stream');
                    if( is_array($attachment) ){
                        $att = array_merge($att, $attachment);
                    }else{
                        $att['path'] = $attachment;
                    }
                    $mail->AddAttachment($att['path'], $att['name'], $att['encoding'], $att['type']);
                }
            }
            do_action('em_mailer', $mail); //$mail will still be modified
            if(is_array($receiver)){
                foreach($receiver as $receiver_email){
                    $mail->AddAddress($receiver_email);
                }
            }else{
                $mail->AddAddress($receiver);
            }

            //Protocols
            if( get_option('dbem_rsvp_mail_send_method') == 'qmail' ){
                $mail->isQmail();
            }elseif( get_option('dbem_rsvp_mail_send_method') == 'sendmail' ){
                $mail->isSendmail();
            }else {
                $mail->Mailer = get_option('dbem_rsvp_mail_send_method');
            }
            if(get_option('dbem_rsvp_mail_SMTPAuth') == '1'){
                $mail->SMTPAuth = TRUE;
            }
            $send = $mail->Send();
            if(!$send){
                $this->errors[] = $mail->ErrorInfo;
            }
            do_action('em_mailer_sent', $mail, $send); //$mail can still be modified
            return $send;
        }else{
            $this->errors[] = __('Please supply a valid email format.', 'events-manager');
            return false;
        }
    }