From a0ae3290e1b8634239282d085bf493f1b7d9eaed Mon Sep 17 00:00:00 2001
From: Kyle M Hall <kyle@bywatersolutions.com>
Date: Wed, 8 May 2024 06:36:41 -0400
Subject: [PATCH] Bug 31627: Send id in an email header

---
 C4/Letters.pm | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/C4/Letters.pm b/C4/Letters.pm
index 49c6c42797b..c7c76ce8ebe 100644
--- a/C4/Letters.pm
+++ b/C4/Letters.pm
@@ -1464,11 +1464,10 @@ sub _send_message_by_email {
             $email->create($params);
         } else {
             $email = Koha::Email->create($params);
+            $email->header('X-Koha-Message-ID', $message->{id} ) if C4::Context->preference('SendLetterIdInEmailNotices');
             if ($is_html) {
-                $content .= "<span id='letter_id' style='display:none'>$message->{letter_id}</span>" if $message->{id} && C4::Context->preference('SendLetterIdInEmailNotices');
                 $email->html_body( _wrap_html( $content, $subject ) );
             } else {
-                $content .= "\n$message->{letter_id}" if $message->{id} && C4::Context->preference('SendLetterIdInEmailNotices');
                 $email->text_body($content);
             }
         }
-- 
2.30.2